https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&feed=atom&action=history UFR 3-12 Best Practice Advice - Revision history 2024-03-29T01:30:48Z Revision history for this page on the wiki MediaWiki 1.39.2 https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=33537&oldid=prev Dave.Ellacott: Dave.Ellacott moved page Silver:UFR 3-12 Best Practice Advice to UFR 3-12 Best Practice Advice over redirect 2017-02-12T13:15:28Z <p>Dave.Ellacott moved page <a href="/w/index.php/Silver:UFR_3-12_Best_Practice_Advice" class="mw-redirect" title="Silver:UFR 3-12 Best Practice Advice">Silver:UFR 3-12 Best Practice Advice</a> to <a href="/w/index.php/UFR_3-12_Best_Practice_Advice" title="UFR 3-12 Best Practice Advice">UFR 3-12 Best Practice Advice</a> over redirect</p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <tr class="diff-title" lang="en"> <td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 13:15, 12 February 2017</td> </tr><tr><td colspan="2" class="diff-notice" lang="en"><div class="mw-diff-empty">(No difference)</div> </td></tr></table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=11057&oldid=prev Niek.verhoeven at 16:41, 29 August 2009 2009-08-29T16:41:22Z <p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:41, 29 August 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l74">Line 74:</td> <td colspan="2" class="diff-lineno">Line 74:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">[[Category:Underlying Flow Regime]]</del></div></td><td colspan="2" class="diff-side-added"></td></tr> </table> Niek.verhoeven https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=8941&oldid=prev Tonyh at 15:51, 15 April 2009 2009-04-15T15:51:35Z <p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:51, 15 April 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l16">Line 16:</td> <td colspan="2" class="diff-lineno">Line 16:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Best Practice Advice for the UFR ==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Best Practice Advice for the UFR ==</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Based on the given example and the examined turbulence models the following best practice advice is proposed for the underlying flow regime &quot;<del style="font-weight: bold; text-decoration: none;">Flow in </del>Stagnation Point&quot;:</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Based on the given example and the examined turbulence models the following best practice advice is proposed for the underlying flow regime &quot;Stagnation Point <ins style="font-weight: bold; text-decoration: none;">Flow</ins>&quot;:</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Key physics ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Key physics ===</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Fluid impinging on a solid surface results in a stagnation point, i.e. the fluid is decelerated. This <del style="font-weight: bold; text-decoration: none;">results in an adverse pressure gradient which may lead to separation. The stagnation </del>point is <del style="font-weight: bold; text-decoration: none;">in any case </del>the starting point of the boundary layer growth. <del style="font-weight: bold; text-decoration: none;">For technical relevant applications </del>the <del style="font-weight: bold; text-decoration: none;">flow </del>is <del style="font-weight: bold; text-decoration: none;">turbulent</del>. <del style="font-weight: bold; text-decoration: none;">Therefore, the development of the </del>boundary layer <del style="font-weight: bold; text-decoration: none;">depends strongly on </del>the turbulence <del style="font-weight: bold; text-decoration: none;">intensity</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Fluid impinging on a solid surface results in a stagnation point, i.e. the fluid is decelerated <ins style="font-weight: bold; text-decoration: none;">with consequences on the turbulence production and hence the development of any free-stream turbulence approaching the stagnation point</ins>. This point is the starting point of the boundary layer growth. <ins style="font-weight: bold; text-decoration: none;">In general, </ins>the <ins style="font-weight: bold; text-decoration: none;">boundary layer </ins>is <ins style="font-weight: bold; text-decoration: none;">initially laminar and then undergoes transition to turbulence some place downstream</ins>. <ins style="font-weight: bold; text-decoration: none;">This </ins>boundary<ins style="font-weight: bold; text-decoration: none;">-</ins>layer <ins style="font-weight: bold; text-decoration: none;">development is quite sensitive to </ins>the turbulence <ins style="font-weight: bold; text-decoration: none;">prevailing in the stagnation region which is swept downstream in the free stream</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>=== <del style="font-weight: bold; text-decoration: none;">Generality </del>of advice given ===</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>=== <ins style="font-weight: bold; text-decoration: none;">Basis </ins>of advice given ===</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained <del style="font-weight: bold; text-decoration: none;">form </del>calculations with the original k-&amp;epsilon; and different modifications thereof (k-&amp;epsilon; with T bound, Kato-Launders k-&amp;epsilon; v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained <ins style="font-weight: bold; text-decoration: none;">from </ins>calculations with the original k-&amp;epsilon; and different modifications thereof (k-&amp;epsilon; with T bound, Kato-Launders k-&amp;epsilon; v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case<ins style="font-weight: bold; text-decoration: none;">, namely the flow around a turbine rotor blade</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Numerical issues ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Numerical issues ===</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l50">Line 50:</td> <td colspan="2" class="diff-lineno">Line 50:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Instead of <del style="font-weight: bold; text-decoration: none;">using </del>the standard k-<del style="font-weight: bold; text-decoration: none;">&amp;</del>epsilon<del style="font-weight: bold; text-decoration: none;">; </del>or k-<del style="font-weight: bold; text-decoration: none;">&amp;</del>omega<del style="font-weight: bold; text-decoration: none;">; </del>model, the <del style="font-weight: bold; text-decoration: none;">v&lt;sup&gt;2&lt;/sup&gt;</del>-f model <del style="font-weight: bold; text-decoration: none;">could </del>be used. <del style="font-weight: bold; text-decoration: none;">Other possibilities would be a </del>bound on the time scale or <del style="font-weight: bold; text-decoration: none;">a </del>modification of the production term.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* Instead of the standard k-epsilon or k-omega <ins style="font-weight: bold; text-decoration: none;"> </ins>model, the <ins style="font-weight: bold; text-decoration: none;">v2</ins>-f model <ins style="font-weight: bold; text-decoration: none;">should </ins>be used <ins style="font-weight: bold; text-decoration: none;">which gave the best results</ins>. <ins style="font-weight: bold; text-decoration: none;">Improvement was also achieved by using Durbin's </ins>bound on the time scale or <ins style="font-weight: bold; text-decoration: none;">the Kato-Launder </ins>modification of the production term<ins style="font-weight: bold; text-decoration: none;">. Explicit transition modelling may be necessary when using such models</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Near wall modelling</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Near wall modelling</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l60">Line 60:</td> <td colspan="2" class="diff-lineno">Line 60:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The heat transfer at the leading edge was obviously affected by the cooling wholes even without coolant flow.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The heat transfer at the leading edge was obviously affected by the cooling wholes even without coolant flow.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Since the turbulence level has <del style="font-weight: bold; text-decoration: none;">a major </del>impact on the heat transfer its <del style="font-weight: bold; text-decoration: none;">correct </del>value is of utmost importance.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* Since the turbulence level <ins style="font-weight: bold; text-decoration: none;">of the approach flow </ins>has <ins style="font-weight: bold; text-decoration: none;">an </ins>impact on the heat transfer<ins style="font-weight: bold; text-decoration: none;">, reliable knowledge of </ins>its value is of utmost importance.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Further work ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Further work ===</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Application of a Reynolds Stress Transport Model (RSTM) on the same test case.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Application of a Reynolds Stress Transport Model (RSTM) on the same test case<ins style="font-weight: bold; text-decoration: none;">. Also, consideration of transition and use of transition models. Study of different cases for which not only heat transfer has been measured</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;font size=&quot;-2&quot; color=&quot;#888888&quot;&gt;© copyright ERCOFTAC 2004&lt;/font&gt;&lt;br /&gt;</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;font size=&quot;-2&quot; color=&quot;#888888&quot;&gt;© copyright ERCOFTAC 2004&lt;/font&gt;&lt;br /&gt;</div></td></tr> </table> Tonyh https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=8430&oldid=prev Daveg: UFR 3-12 Best Practice Advice moved to Silver:UFR 3-12 Best Practice Advice 2009-04-07T12:22:12Z <p><a href="/w/index.php/UFR_3-12_Best_Practice_Advice" title="UFR 3-12 Best Practice Advice">UFR 3-12 Best Practice Advice</a> moved to <a href="/w/index.php/Silver:UFR_3-12_Best_Practice_Advice" class="mw-redirect" title="Silver:UFR 3-12 Best Practice Advice">Silver:UFR 3-12 Best Practice Advice</a></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <tr class="diff-title" lang="en"> <td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 12:22, 7 April 2009</td> </tr><tr><td colspan="2" class="diff-notice" lang="en"><div class="mw-diff-empty">(No difference)</div> </td></tr></table> Daveg https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=5114&oldid=prev David.Fowler at 17:17, 11 March 2009 2009-03-11T17:17:51Z <p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 17:17, 11 March 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l31">Line 31:</td> <td colspan="2" class="diff-lineno">Line 30:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Discretisation method</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Discretisation method</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>In order to minimise numerical diffusion a higher order discretisation scheme should be used.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>In order to minimise numerical diffusion a higher order discretisation scheme should be used.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>With the given considerations of the turbulent flow an elliptic solver should be used.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>With the given considerations of the turbulent flow an elliptic solver should be used.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Grid and grid resolution</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Grid and grid resolution</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>Grid cell aspect ratio close to unity around the stagnation point area.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>Grid cell aspect ratio close to unity around the stagnation point area.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>Grid point distribution according to the recommended standard values for two-equation models.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>Grid point distribution according to the recommended standard values for two-equation models.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Computational domain &amp;amp; boundary conditions ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Computational domain &amp;amp; boundary conditions ===</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>Inlet and outlet of the grid have to be placed sufficiently far away of the stagnation point, although through the (almost) parabolic nature of this flow problem the upstream boundary can be placed closer to the stagnation point than the downstream boundary.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>Inlet and outlet of the grid have to be placed sufficiently far away of the stagnation point, although through the (almost) parabolic nature of this flow problem the upstream boundary can be placed closer to the stagnation point than the downstream boundary.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>The outflow should be described as a Neumann boundary condition.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>The outflow should be described as a Neumann boundary condition.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Physical modelling ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Physical modelling ===</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l51">Line 51:</td> <td colspan="2" class="diff-lineno">Line 50:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>Instead of using the standard k-<del style="font-weight: bold; text-decoration: none;">ε </del>or k-<del style="font-weight: bold; text-decoration: none;">ω </del>model, the v&lt;sup&gt;2&lt;/sup&gt;-f model could be used. Other possibilities would be a bound on the time scale or a modification of the production term.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>Instead of using the standard k-<ins style="font-weight: bold; text-decoration: none;">&amp;epsilon; </ins>or k-<ins style="font-weight: bold; text-decoration: none;">&amp;omega; </ins>model, the v&lt;sup&gt;2&lt;/sup&gt;-f model could be used. Other possibilities would be a bound on the time scale or a modification of the production term.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Near wall modelling</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Near wall modelling</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>The first grid point above the solid surface should be placed appropriate to the requirement of the model.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>The first grid point above the solid surface should be placed appropriate to the requirement of the model.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Application uncertainties</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Application uncertainties</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>The heat transfer at the leading edge was obviously affected by the cooling wholes even without coolant flow.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>The heat transfer at the leading edge was obviously affected by the cooling wholes even without coolant flow.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;</del>Since the turbulence level has a major impact on the heat transfer its correct value is of utmost importance.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* </ins>Since the turbulence level has a major impact on the heat transfer its correct value is of utmost importance.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Further work ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Further work ===</div></td></tr> </table> David.Fowler https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=5113&oldid=prev David.Fowler: /* Generality of advice given */ 2009-03-11T17:16:27Z <p><span dir="auto"><span class="autocomment">Generality of advice given</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 17:16, 11 March 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l25">Line 25:</td> <td colspan="2" class="diff-lineno">Line 25:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Generality of advice given ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Generality of advice given ===</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained form calculations with the original k-<del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e &lt;/font&gt;&lt;/span&gt;</del>and different modifications thereof (k-<del style="font-weight: bold; text-decoration: none;">ε </del>with T bound, Kato-Launders k-<del style="font-weight: bold; text-decoration: none;">&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e,&lt;/font&gt;&lt;/span&gt; </del>v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained form calculations with the original k-<ins style="font-weight: bold; text-decoration: none;">&amp;epsilon; </ins>and different modifications thereof (k-<ins style="font-weight: bold; text-decoration: none;">&amp;epsilon; </ins>with T bound, Kato-Launders k-<ins style="font-weight: bold; text-decoration: none;">&amp;epsilon; </ins>v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Numerical issues ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Numerical issues ===</div></td></tr> </table> David.Fowler https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=4000&oldid=prev David.Fowler: /* Best Practice Advice for the UFR */ 2009-03-08T11:07:43Z <p><span dir="auto"><span class="autocomment">Best Practice Advice for the UFR</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:07, 8 March 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l19">Line 19:</td> <td colspan="2" class="diff-lineno">Line 19:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Based on the given example and the examined turbulence models the following best practice advice is proposed for the underlying flow regime &quot;Flow in Stagnation Point&quot;:</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Based on the given example and the examined turbulence models the following best practice advice is proposed for the underlying flow regime &quot;Flow in Stagnation Point&quot;:</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Key physics<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Key physics <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fluid impinging on a solid surface results in a stagnation point, i.e. the fluid is decelerated. This results in an adverse pressure gradient which may lead to separation. The stagnation point is in any case the starting point of the boundary layer growth. For technical relevant applications the flow is turbulent. Therefore, the development of the boundary layer depends strongly on the turbulence intensity.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fluid impinging on a solid surface results in a stagnation point, i.e. the fluid is decelerated. This results in an adverse pressure gradient which may lead to separation. The stagnation point is in any case the starting point of the boundary layer growth. For technical relevant applications the flow is turbulent. Therefore, the development of the boundary layer depends strongly on the turbulence intensity.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Generality of advice given<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Generality of advice given <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained form calculations with the original k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e &lt;/font&gt;&lt;/span&gt;and different modifications thereof (k-ε with T bound, Kato-Launders k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e,&lt;/font&gt;&lt;/span&gt; v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained form calculations with the original k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e &lt;/font&gt;&lt;/span&gt;and different modifications thereof (k-ε with T bound, Kato-Launders k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e,&lt;/font&gt;&lt;/span&gt; v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Numerical issues<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Numerical issues <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Discretisation method</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Discretisation method</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l41">Line 41:</td> <td colspan="2" class="diff-lineno">Line 41:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Grid point distribution according to the recommended standard values for two-equation models.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Grid point distribution according to the recommended standard values for two-equation models.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Computational domain &amp;amp; boundary conditions<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Computational domain &amp;amp; boundary conditions <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Inlet and outlet of the grid have to be placed sufficiently far away of the stagnation point, although through the (almost) parabolic nature of this flow problem the upstream boundary can be placed closer to the stagnation point than the downstream boundary.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Inlet and outlet of the grid have to be placed sufficiently far away of the stagnation point, although through the (almost) parabolic nature of this flow problem the upstream boundary can be placed closer to the stagnation point than the downstream boundary.</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l47">Line 47:</td> <td colspan="2" class="diff-lineno">Line 47:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;The outflow should be described as a Neumann boundary condition.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;The outflow should be described as a Neumann boundary condition.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Physical modelling<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Physical modelling <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Turbulence modelling</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l63">Line 63:</td> <td colspan="2" class="diff-lineno">Line 63:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Since the turbulence level has a major impact on the heat transfer its correct value is of utmost importance.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>&lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Since the turbulence level has a major impact on the heat transfer its correct value is of utmost importance.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''</del>Further work<del style="font-weight: bold; text-decoration: none;">'''</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=== </ins>Further work <ins style="font-weight: bold; text-decoration: none;">===</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Application of a Reynolds Stress Transport Model (RSTM) on the same test case.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Application of a Reynolds Stress Transport Model (RSTM) on the same test case.</div></td></tr> </table> David.Fowler https://kbwiki.ercoftac.org/w/index.php?title=UFR_3-12_Best_Practice_Advice&diff=3449&oldid=prev David.Fowler: New page: {{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestp... 2009-03-06T14:34:19Z <p>New page: {{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestp...</p> <p><b>New page</b></p><div><br /> {{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}<br /> <br /> <br /> {{Status|checked=no|by= |date= }}<br /> <br /> <br /> <br /> = Stagnation point flow =<br /> <br /> Underlying Flow Regime 3-12 &lt;font size=&quot;-2&quot; color=&quot;#888888&quot;&gt;               © copyright ERCOFTAC 2004&lt;/font&gt;<br /> <br /> <br /> <br /> = Best Practice Advice =<br /> <br /> == Best Practice Advice for the UFR ==<br /> <br /> Based on the given example and the examined turbulence models the following best practice advice is proposed for the underlying flow regime &quot;Flow in Stagnation Point&quot;:<br /> <br /> '''Key physics'''<br /> <br /> Fluid impinging on a solid surface results in a stagnation point, i.e. the fluid is decelerated. This results in an adverse pressure gradient which may lead to separation. The stagnation point is in any case the starting point of the boundary layer growth. For technical relevant applications the flow is turbulent. Therefore, the development of the boundary layer depends strongly on the turbulence intensity.<br /> <br /> '''Generality of advice given'''<br /> <br /> The BPA is based on the consideration of the theoretical background of two-equation turbulence models. Furthermore, this BPA is supported by the results gained form calculations with the original k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e &lt;/font&gt;&lt;/span&gt;and different modifications thereof (k-ε with T bound, Kato-Launders k-&lt;span&gt;&lt;font face=&quot;Symbol&quot;&gt;e,&lt;/font&gt;&lt;/span&gt; v&lt;sup&gt;2&lt;/sup&gt;-f) which are all applied to a single test case.<br /> <br /> '''Numerical issues'''<br /> <br /> Discretisation method<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;In order to minimise numerical diffusion a higher order discretisation scheme should be used.<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;With the given considerations of the turbulent flow an elliptic solver should be used.<br /> <br /> Grid and grid resolution<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Grid cell aspect ratio close to unity around the stagnation point area.<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Grid point distribution according to the recommended standard values for two-equation models.<br /> <br /> '''Computational domain &amp;amp; boundary conditions'''<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Inlet and outlet of the grid have to be placed sufficiently far away of the stagnation point, although through the (almost) parabolic nature of this flow problem the upstream boundary can be placed closer to the stagnation point than the downstream boundary.<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;The outflow should be described as a Neumann boundary condition.<br /> <br /> '''Physical modelling'''<br /> <br /> Turbulence modelling<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Instead of using the standard k-ε or k-ω model, the v&lt;sup&gt;2&lt;/sup&gt;-f model could be used. Other possibilities would be a bound on the time scale or a modification of the production term.<br /> <br /> Near wall modelling<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;The first grid point above the solid surface should be placed appropriate to the requirement of the model.<br /> <br /> Application uncertainties<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;The heat transfer at the leading edge was obviously affected by the cooling wholes even without coolant flow.<br /> <br /> &lt;span&gt;&lt;font face=&quot;Wingdings&quot;&gt;§&lt;span style=&quot;font: 7.0pt &amp;quot;Times New Roman&amp;quot;&quot;&gt;         &lt;/span&gt;&lt;/font&gt;&lt;/span&gt;Since the turbulence level has a major impact on the heat transfer its correct value is of utmost importance.<br /> <br /> '''Further work'''<br /> <br /> Application of a Reynolds Stress Transport Model (RSTM) on the same test case.<br /> <br /> &lt;font size=&quot;-2&quot; color=&quot;#888888&quot;&gt;© copyright ERCOFTAC 2004&lt;/font&gt;&lt;br /&gt;<br /> ----<br /> <br /> <br /> Contributors: Beat Ribi - MAN Turbomaschinen AG Schweiz<br /> <br /> <br /> {{UFR|front=UFR 3-12|description=UFR 3-12 Description|references=UFR 3-12 References|testcase=UFR 3-12 Test Case|evaluation=UFR 3-12 Evaluation|qualityreview=UFR 3-12 Quality Review|bestpractice=UFR 3-12 Best Practice Advice|relatedACs=UFR 3-12 Related ACs}}<br /> <br /> <br /> [[Category:Underlying Flow Regime]]</div> David.Fowler