https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&feed=atom&action=history UFR 4-10 Test Case - Revision history 2024-03-28T23:09:53Z Revision history for this page on the wiki MediaWiki 1.39.2 https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=33837&oldid=prev Dave.Ellacott: Dave.Ellacott moved page Silver:UFR 4-10 Test Case to UFR 4-10 Test Case over redirect 2017-02-12T14:24:12Z <p>Dave.Ellacott moved page <a href="/w/index.php/Silver:UFR_4-10_Test_Case" class="mw-redirect" title="Silver:UFR 4-10 Test Case">Silver:UFR 4-10 Test Case</a> to <a href="/w/index.php/UFR_4-10_Test_Case" title="UFR 4-10 Test Case">UFR 4-10 Test Case</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 14:24, 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_4-10_Test_Case&diff=22077&oldid=prev Dave.Ellacott: /* Wall treatment */ 2011-09-28T08:09:22Z <p><span dir="auto"><span class="autocomment">Wall treatment</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 08:09, 28 September 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l78">Line 78:</td> <td colspan="2" class="diff-lineno">Line 78:</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>'''''Treatment of turbulent heat fluxes'''''</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>'''''Treatment of turbulent heat fluxes'''''</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^{\,2}&lt;/math&gt; [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^{\,2}&lt;/math&gt; <ins style="font-weight: bold; text-decoration: none;">&lt;!--</ins>[[Image:U4-10d32_files_image032.gif]]<ins style="font-weight: bold; text-decoration: none;">--&gt; </ins>(analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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>== Large-eddy simulations ==</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>== Large-eddy simulations ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=22076&oldid=prev Dave.Ellacott: /* Wall treatment */ 2011-09-28T08:09:01Z <p><span dir="auto"><span class="autocomment">Wall treatment</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 08:09, 28 September 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l78">Line 78:</td> <td colspan="2" class="diff-lineno">Line 78:</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>'''''Treatment of turbulent heat fluxes'''''</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>'''''Treatment of turbulent heat fluxes'''''</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^{\ 2}&lt;/math&gt; [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^{\<ins style="font-weight: bold; text-decoration: none;">,</ins>2}&lt;/math&gt; [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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>== Large-eddy simulations ==</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>== Large-eddy simulations ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=22075&oldid=prev Dave.Ellacott: /* Wall treatment */ 2011-09-28T08:07:08Z <p><span dir="auto"><span class="autocomment">Wall treatment</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 08:07, 28 September 2011</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;"><div>'''''Treatment of Reynolds stresses'''''</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>'''''Treatment of Reynolds stresses'''''</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 approaches adopted in representing the turbulent stresses appearing in the momentum equations can largely be divided into three groups: ''linear eddy-viscosity models'' (EVM), ''algebraic-stress'' (ASM) or ''non-linear models'' and full ''Reynolds-stress transport models'' (RSTM). The vast majority of EVM publications in this context are based on variants of the ''k-''&amp;epsilon; model, examples being Betts and <del style="font-weight: bold; text-decoration: none;">Dafa’Alla </del>[4], Davidson [14] and Ince and Launder [38], with LRN wall treatments, and Markatos and Pericleous [47] and Thompson ''et al''. [59] with wall functions. Examples of the ASM approach include Humphrey and To [37], Davidson [15], Shabbir and Taulbee [58], Muramatsu and Ninokata [49], Liu and Wen [45] and Wen ''et al.'' [65]. The application of full RSTMs in this context has been relatively rare however examples include: Dol ''et al''. [19], Chang and Bottoni [8] and Boudjemadi ''et al.'' [6].</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 approaches adopted in representing the turbulent stresses appearing in the momentum equations can largely be divided into three groups: ''linear eddy-viscosity models'' (EVM), ''algebraic-stress'' (ASM) or ''non-linear models'' and full ''Reynolds-stress transport models'' (RSTM). The vast majority of EVM publications in this context are based on variants of the ''k-''&amp;epsilon; model, examples being Betts and <ins style="font-weight: bold; text-decoration: none;">Dafa&amp;rsquo;Alla </ins>[4], Davidson [14] and Ince and Launder [38], with LRN wall treatments, and Markatos and Pericleous [47] and Thompson ''et al''. [59] with wall functions. Examples of the ASM approach include Humphrey and To [37], Davidson [15], Shabbir and Taulbee [58], Muramatsu and Ninokata [49], Liu and Wen [45] and Wen ''et al.'' [65]. The application of full RSTMs in this context has been relatively rare however examples include: Dol ''et al''. [19], Chang and Bottoni [8] and Boudjemadi ''et al.'' [6].</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>'''''Treatment of turbulent heat fluxes'''''</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>'''''Treatment of turbulent heat fluxes'''''</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^2&lt;/math&gt; [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, &lt;math&gt;\bar{\theta}^<ins style="font-weight: bold; text-decoration: none;">{\ </ins>2<ins style="font-weight: bold; text-decoration: none;">}</ins>&lt;/math&gt; [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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>== Large-eddy simulations ==</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>== Large-eddy simulations ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=22074&oldid=prev Dave.Ellacott: /* Wall treatment */ 2011-09-28T08:06:24Z <p><span dir="auto"><span class="autocomment">Wall treatment</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 08:06, 28 September 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l78">Line 78:</td> <td colspan="2" class="diff-lineno">Line 78:</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>'''''Treatment of turbulent heat fluxes'''''</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>'''''Treatment of turbulent heat fluxes'''''</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to Fourier's law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and Dafa&amp;rsquo;Alla [4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, <ins style="font-weight: bold; text-decoration: none;">&lt;math&gt;\bar{\theta}^2&lt;/math&gt; </ins>[[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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>== Large-eddy simulations ==</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>== Large-eddy simulations ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=22073&oldid=prev Dave.Ellacott: /* Wall treatment */ 2011-09-28T08:05:24Z <p><span dir="auto"><span class="autocomment">Wall treatment</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 08:05, 28 September 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l78">Line 78:</td> <td colspan="2" class="diff-lineno">Line 78:</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>'''''Treatment of turbulent heat fluxes'''''</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>'''''Treatment of turbulent heat fluxes'''''</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to <del style="font-weight: bold; text-decoration: none;">Fourier’s </del>law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and <del style="font-weight: bold; text-decoration: none;">Dafa’Alla </del>[4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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 simplest representation used for the turbulent heat fluxes is to assume a linear isotropic form, analogous to <ins style="font-weight: bold; text-decoration: none;">Fourier's </ins>law, with the eddy diffusivity calculated from the eddy viscosity using the assumption of a constant turbulent Prandtl number (''Pr&lt;sub&gt;t&lt;/sub&gt;''). This appears in some earlier studies ''e.g''. Betts and <ins style="font-weight: bold; text-decoration: none;">Dafa&amp;rsquo;Alla </ins>[4], Davidson [14] and Markatos and Pericleous [47] however it has fallen out of favour due to the importance of counter-gradient diffusion effects in turbulent buoyant flows [42]. Another gradient-based approach commonly used is the generalised gradient-diffusion hypothesis (GGDH) of Daly and Harlow, see [41], which does not assume a constant ''Pr&lt;sub&gt;t&lt;/sub&gt;'', one example being the study of Ince and Launder [38]. More sophisticated approaches use one- or two-equation models for the transport and production/destruction of the temperature variance, [[Image:U4-10d32_files_image032.gif]] (analogous to the turbulence kinetic energy) and its dissipation rate, &amp;epsilon;. These can either be used to calculate a single isotropic eddy diffusivity, as in the model of Abe ''et al.'' [1], or combined with anisotropic algebraic expressions for the turbulent heat fluxes, as in the algebraic-flux models (AFM) of Hanjalić ''et al.'' [30-33].</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>== Large-eddy simulations ==</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>== Large-eddy simulations ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=22072&oldid=prev Dave.Ellacott: /* Test Case Experiments */ 2011-09-28T08:04:51Z <p><span dir="auto"><span class="autocomment">Test Case Experiments</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 08:04, 28 September 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l32">Line 32:</td> <td colspan="2" class="diff-lineno">Line 32:</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>== Test Case Experiments ==</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>== Test Case Experiments ==</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>A previously used experimental rig (that of Betts and <del style="font-weight: bold; text-decoration: none;">Dafa’Alla </del>[4, 13]) was modified by fitting partially conducting top and bottom walls and outer guard channels, to provide boundary conditions which avoid the inadequately defined sharp changes in temperature gradient and other problems associated with insufficient insulation on nominally adiabatic walls. Mean and turbulent temperature and velocity variations within the cavity have been measured, together with heat fluxes and turbulent shear stresses. The partially conducting roof and floor provide locally unstable thermal stratification in the wall jet flows there, which enhances the turbulence as the flow moves towards the temperature controlled plates. The results provide a greatly improved benchmark for the testing of turbulence models in this low turbulence Reynolds number flow. Profiles of mean vertical velocity are given in Figure 5(b) for the Ra=0.86 x 10&lt;sup&gt;6&lt;/sup&gt; case and of the mean temperature at mid-height for both Ra values in Figure 6.</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>A previously used experimental rig (that of Betts and <ins style="font-weight: bold; text-decoration: none;">Dafa&amp;rsquo;Alla </ins>[4, 13]) was modified by fitting partially conducting top and bottom walls and outer guard channels, to provide boundary conditions which avoid the inadequately defined sharp changes in temperature gradient and other problems associated with insufficient insulation on nominally adiabatic walls. Mean and turbulent temperature and velocity variations within the cavity have been measured, together with heat fluxes and turbulent shear stresses. The partially conducting roof and floor provide locally unstable thermal stratification in the wall jet flows there, which enhances the turbulence as the flow moves towards the temperature controlled plates. The results provide a greatly improved benchmark for the testing of turbulence models in this low turbulence Reynolds number flow. Profiles of mean vertical velocity are given in Figure 5(b) for the Ra=0.86 x 10&lt;sup&gt;6&lt;/sup&gt; case and of the mean temperature at mid-height for both Ra values in Figure 6.</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>== ''Experimental rig'' ==</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>== ''Experimental rig'' ==</div></td></tr> </table> Dave.Ellacott https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=11179&oldid=prev Niek.verhoeven at 19:11, 29 August 2009 2009-08-29T19:11:17Z <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 19:11, 29 August 2009</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l92">Line 92:</td> <td colspan="2" class="diff-lineno">Line 92:</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 4-10|description=UFR 4-10 Description|references=UFR 4-10 References|testcase=UFR 4-10 Test Case|evaluation=UFR 4-10 Evaluation|qualityreview=UFR 4-10 Quality Review|bestpractice=UFR 4-10 Best Practice Advice|relatedACs=UFR 4-10 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 4-10|description=UFR 4-10 Description|references=UFR 4-10 References|testcase=UFR 4-10 Test Case|evaluation=UFR 4-10 Evaluation|qualityreview=UFR 4-10 Quality Review|bestpractice=UFR 4-10 Best Practice Advice|relatedACs=UFR 4-10 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_4-10_Test_Case&diff=8807&oldid=prev Tonyh: UFR 4-10 Test Case moved to Silver:UFR 4-10 Test Case 2009-04-07T14:23:39Z <p><a href="/w/index.php/UFR_4-10_Test_Case" title="UFR 4-10 Test Case">UFR 4-10 Test Case</a> moved to <a href="/w/index.php/Silver:UFR_4-10_Test_Case" class="mw-redirect" title="Silver:UFR 4-10 Test Case">Silver:UFR 4-10 Test Case</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 14:23, 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> Tonyh https://kbwiki.ercoftac.org/w/index.php?title=UFR_4-10_Test_Case&diff=7845&oldid=prev Daveg: /* Brief description of the study test case */ 2009-04-03T20:10:53Z <p><span dir="auto"><span class="autocomment">Brief description of the study test case</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 20:10, 3 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>== Brief description of the study 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>== Brief description of the study 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>The test case chosen consists of measurements of turbulent buoyancy-driven flow in a tall cavity carried out by Betts and Bokhari [3, 5] at UMIST. This case was one of those considered in the 5&lt;sup&gt;th&lt;/sup&gt; ERCOFTAC/IAHR Workshop on Refined Flow Modelling in 1996 [24]. The measurement data are available in the ERCOFTAC database:[http://cfd.mace.manchester.ac.uk/cgi-bin/cfddb/prpage.cgi?79&amp;EXP&amp;database/cases/case79/Case_data&amp;database/cases/case79&amp;cas79_head.html&amp;cas79_desc.html&amp;cas79_meth.html&amp;cas79_data.html&amp;cas79_refs.html&amp;cas79_rsol.html&amp;1&amp;0&amp;0&amp;0&amp;0 Case 79<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>The test case chosen consists of measurements of turbulent buoyancy-driven flow in a tall cavity carried out by Betts and Bokhari [3, 5] at UMIST. This case was one of those considered in the 5&lt;sup&gt;th&lt;/sup&gt; ERCOFTAC/IAHR Workshop on Refined Flow Modelling in 1996 [24]. The measurement data are available in the ERCOFTAC database:[http://cfd.mace.manchester.ac.uk/cgi-bin/cfddb/prpage.cgi?79&amp;EXP&amp;database/cases/case79/Case_data&amp;database/cases/case79&amp;cas79_head.html&amp;cas79_desc.html&amp;cas79_meth.html&amp;cas79_data.html&amp;cas79_refs.html&amp;cas79_rsol.html&amp;1&amp;0&amp;0&amp;0&amp;0 Case 79] or directly from UMIST: http://cfd.me.umist.ac.uk/tmcfd/expdata/bettbok.html. Conditions at the mid-height of the cavity approximate to those in an infinitely tall cavity, allowing comparison at that location with the DNS data ofBoudjemadi ''et al.'' [6] and Versteegh and Nieuwstadt [63] (see http://tmdb.ws.tn.tudelft.nl/workshop5.html). It should be noted that the DNS data do not agree with each other in all respects and also do not agree fully with the experimental data for some quantities. Dol ''et al.'' [19] judged the data of [63] to be the more reliable of the two DNS data sets.</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> </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;">[http://cfd.me.umist.ac.uk/ercoftac/ http://cfd.me.umist.ac.uk/ercoftac</del>] or directly from UMIST: http://cfd.me.umist.ac.uk/tmcfd/expdata/bettbok.html. Conditions at the mid-height of the cavity approximate to those in an infinitely tall cavity, allowing comparison at that location with the DNS data ofBoudjemadi ''et al.'' [6] and Versteegh and Nieuwstadt [63] (see http://tmdb.ws.tn.tudelft.nl/workshop5.html). It should be noted that the DNS data do not agree with each other in all respects and also do not agree fully with the experimental data for some quantities. Dol ''et al.'' [19] judged the data of [63] to be the more reliable of the two DNS data sets.</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;"><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 experiments were undertaken to investigate the natural convection of air in a tall differentially-heated rectangular cavity (2.18m high by 0.076m wide by 0.52m in depth, aspect ratio 28.6:1) shown diagrammatically in Figure 5(a). They were performed with temperature differentials between the vertical plates of 19.6 and 39.9 &amp;deg;C, giving Rayleigh numbers based on the width of 0.86x10&lt;sup&gt;6&lt;/sup&gt; and 1.43x10&lt;sup&gt;6&lt;/sup&gt;, respectively. The non-dimensional temperature differences, &amp;theta;, are 0.033 and 0.064, respectively, placing the flow well within the Boussinesq regime. The resulting mean Nusselt numbers across the cavity are 5.85 for the lower Ra and 7.57 for the higher. Under these conditions the flow in the core of the cavity is fully turbulent and property variations with temperature are comparatively small. The temperature and flow fields were found to be closely two-dimensional, except close to the front and back walls, and anti-symmetric across the diagonal of the cavity (as should be the case given the low temperature differential). The differing thermal stratification across the top and bottom walls observed in many earlier experiments has been removed.</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 experiments were undertaken to investigate the natural convection of air in a tall differentially-heated rectangular cavity (2.18m high by 0.076m wide by 0.52m in depth, aspect ratio 28.6:1) shown diagrammatically in Figure 5(a). They were performed with temperature differentials between the vertical plates of 19.6 and 39.9 &amp;deg;C, giving Rayleigh numbers based on the width of 0.86x10&lt;sup&gt;6&lt;/sup&gt; and 1.43x10&lt;sup&gt;6&lt;/sup&gt;, respectively. The non-dimensional temperature differences, &amp;theta;, are 0.033 and 0.064, respectively, placing the flow well within the Boussinesq regime. The resulting mean Nusselt numbers across the cavity are 5.85 for the lower Ra and 7.57 for the higher. Under these conditions the flow in the core of the cavity is fully turbulent and property variations with temperature are comparatively small. The temperature and flow fields were found to be closely two-dimensional, except close to the front and back walls, and anti-symmetric across the diagonal of the cavity (as should be the case given the low temperature differential). The differing thermal stratification across the top and bottom walls observed in many earlier experiments has been removed.</div></td></tr> </table> Daveg