CFD Simulations AC 7 01

Thoughts of a poor old sod

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Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

Overview of CFD Simulations

If CFD simulations of the AC have been performed then provide a brief overview. This should cover the scope of the calculations and the main aspects of the modelling strategy e.g. equations solved, turbulence and other physical models employed). All computational domain simplifications/idealisations, and the treatment of subgrid features should also be identified (e.g. imposed symmetry plane, omission of detailed features, simplification of complex/small scale features, i.e. porous media, use of equivalent wall roughness). If important details of the geometry representation are uncertain then the impact of these uncertainties on the DOAPs should be discussed, including possible ways for managing their effect.

It is left to the discretion of each author to decide the most appropriate way for structuring and summarising the CFD results. Ideally, the data structures used should be consistent with those used for the test data.

A summary table for all CFD simulation results should be included, as shown below in Table CFD-A. Available data should be clearly identified, (e.g. UVW, k, concentration, etc). As with test data, a distinction should be drawn between detailed local data (e.g. p(x,y,z)) and data relating to DOAPs which are likely to be global/summary parameters (e.g. coefficient of lift, CL).

All available detailed data should be stored in separate electronic datafiles (according to guidelines set out by the Knowledge Base team at the University of Surrey). These should be summarised as shown below in CFD-B, with links to each of the datafiles.

Table CFD-A Summary description of all test cases

Name	GNDPs		PDPs (problem definition parameters)			MPs (measured parameters)
	Re	Fr	Wind direction	Source rate (kg/s)	Release density(kg/m3)	Detailed data	DOAPs
CFD 1 (dense gas dispersion)	$10^{5}-10^{6}$	$0.2-10$	0, 30, 45, 90, 180	$1-3$	$1.22-3.00$	$C,\ U$	${\ C/C_{0}}$
	Re		Wind direction	Building geometry		Detailed data	DOAPs
CFD 2 (passive gas releases)	$10^{5}-10^{6}$		0, 30, 45	A, B, C, D		$C,\ U,\ V,\ W,\ k$	${\ C/C_{0}}$

Table CFD-B Summary description of all available datafiles and simulated parameters

	SP1 $U,\ V,\ W\ (ms^{-1})$	SP2 $k\ (m^{2}s^{-2})$	SP3 $C\ (kg/m^{3})$	DOAPs, or other miscellaneous data
CFD 1	✔✔✔ cfd11.dat	✔	✔ cfd13.dat	cfd14.dat, cfd15.dat
CFD 2	✔✔✔ cfd21.dat	✔ cfd22.dat	✔ cfd23.dat	cfd24.dat, cfd25.dat,  cfd26.dat

SIMULATION CASE CFD1

Solution Strategy

A self-contained description of the solution strategy employed. This should include:

• the name of the code (including version number)

• all equations solved, including the turbulence model, and any other physical model used (e.g. chemistry, pollutant transport)

• the numerical discretisation scheme used in both space and time (this may depend on the equation set solved, e.g. momentum equations may be different from the turbulence equations)

• the solution algorithm used

Computational Domain

Describe the geometry of the computational domain including the location of all boundaries. Does this domain coincide with the test geometry or does it represent a simplification? Discuss the impact of any simplification on the DOAPs. In particular justify any 2-D idealisation. Describe in detail the mesh (or meshes) used, including the total number of cells/grid points and mesh density distribution.

Boundary Conditions

Describe the numerical boundary conditions at all boundaries including inflows, symmetry surfaces, walls, far-fields, free surfaces and outflows. In each case, comment on how these replicate conditions in the test rig (e.g. inflow conditions based on measured data taken at a rig measurement station?). Have sensitivity tests been carried out to explore the effect of uncertainties in boundary conditions (e.g. turbulence data at inflow, position of far field boundaries, etc.)

Application of Physical Models

Describe the details of how turbulence models, and any other physical models, were applied For example if RANS turbulence models have been used what is the near wall set-up? What is y+ at the first grid point from the wall (y is normal distance to the wall) and how many grid points lie in the wall boundary layer? (the type of wall treatment employed, i.e. wall functions or low Reynolds number turbulence model is described in the Boundary Conditions subsection above).

Numerical Accuracy

What steps have been taken to estimate or demonstrate the numerical accuracy of the results (e.g. mesh and time-step refinement studies, increasing the order of accuracy of the scheme)? What measure of iteration convergence was used, and was this achieved?

CFD Results

List data included, with links to all data files. Describe the data storage format used, and specify conventions (define reference coordinate system, and state if data are vertex, cell-centered, or interpolated).

For example:

CFD1 Dense gas release simulation: RANS calculations, standard k-ε, coordinate system as per experiments, cell-centred data

cfd11.dat binary file; headers: Re, Fr, wind direction, source rate, release density;

columns: $x,\ y,\ z,\ U,\ V,\ W$

cfd13.dat binary file; headers: Re, Fr, wind direction, source rate, release density;

columns: $x,\ y,\ z,\ C$

References

Any references in the scientific literature that are relevant; if possible use references that can be accessed via the web and add hyperlink.

• Reference 1
• Reference 2 ...

SIMULATION CASE CFD2

Solution Strategy

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Computational Domain

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Boundary Conditions

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam vulputate, nibh quis dictum cursus, mi felis commodo elit, ac posuere mi quam et dolor. Integer libero ante, posuere quis pharetra in, lobortis non turpis. Proin accumsan, arcu ac facilisis volutpat, purus magna pellentesque mi, vitae porttitor turpis elit eget nisl. Nullam mauris felis, volutpat at vehicula quis, pretium at magna. Maecenas tristique erat dolor, sit amet congue eros. Pellentesque commodo neque consectetur orci sodales bibendum. Praesent interdum urna a mauris cursus et eleifend leo auctor. Aliquam vel eros ac diam accumsan dignissim. In mollis erat eget massa dictum faucibus. Etiam a erat eu erat blandit accumsan. Vivamus ac justo quis ante dignissim cursus vitae sit amet sapien. Nam urna tortor, molestie et porta eu, iaculis at ipsum. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Suspendisse eu libero ac odio ornare vehicula. Maecenas luctus aliquam lectus sit amet accumsan.

Application of Physical Models

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Numerical Accuracy

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam vulputate, nibh quis dictum cursus, mi felis commodo elit, ac posuere mi quam et dolor. Integer libero ante, posuere quis pharetra in, lobortis non turpis. Proin accumsan, arcu ac facilisis volutpat, purus magna pellentesque mi, vitae porttitor turpis elit eget nisl. Nullam mauris felis, volutpat at vehicula quis, pretium at magna. Maecenas tristique erat dolor, sit amet congue eros. Pellentesque commodo neque consectetur orci sodales bibendum. Praesent interdum urna a mauris cursus et eleifend leo auctor. Aliquam vel eros ac diam accumsan dignissim. In mollis erat eget massa dictum faucibus. Etiam a erat eu erat blandit accumsan. Vivamus ac justo quis ante dignissim cursus vitae sit amet sapien. Nam urna tortor, molestie et porta eu, iaculis at ipsum. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Suspendisse eu libero ac odio ornare vehicula. Maecenas luctus aliquam lectus sit amet accumsan.

CFD Results

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam vulputate, nibh quis dictum cursus, mi felis commodo elit, ac posuere mi quam et dolor. Integer libero ante, posuere quis pharetra in, lobortis non turpis. Proin accumsan, arcu ac facilisis volutpat, purus magna pellentesque mi, vitae porttitor turpis elit eget nisl. Nullam mauris felis, volutpat at vehicula quis, pretium at magna. Maecenas tristique erat dolor, sit amet congue eros. Pellentesque commodo neque consectetur orci sodales bibendum. Praesent interdum urna a mauris cursus et eleifend leo auctor. Aliquam vel eros ac diam accumsan dignissim. In mollis erat eget massa dictum faucibus. Etiam a erat eu erat blandit accumsan. Vivamus ac justo quis ante dignissim cursus vitae sit amet sapien. Nam urna tortor, molestie et porta eu, iaculis at ipsum. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Suspendisse eu libero ac odio ornare vehicula. Maecenas luctus aliquam lectus sit amet accumsan.

References

• Reference 1
• Reference 2

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Contributed by: JB Priestley — Yorkshire

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

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