[CFD] What Wall Functions Do I Need for Epsilon?

Описание: [CFD] What Wall Functions Do I Need for Epsilon?

An introduction to the wall functions that are used to capture the near wall behavior of the turbulence dissipation rate (epsilon) in all mainstream CFD codes (OpenFOAM, Fluent, CFX, Star). The following topics are covered:

1) 4:03 How is the wall treatment for epsilon different to velocity and temperature?

2) 12:57 What wall functions do we use for epsilon?

3) 18:18 How do we account for cells with multiple boundary faces?

#wallfunctions #epsilon #epsilonwallfunctions

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Some useful references:
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1) ANSYS FLUENT User Manual
12.10.2 Standard Wall Functions

http://www.afs.enea.it/project/neptun...

2) G. Kalitzin, G. Medic, G. Iaccarino and P. Durbin
Near-wall behaviour of RANS turbulene models and implications for wall functions
Journal of Computational Physics 204 (2005) 265-291

http://citeseerx.ist.psu.edu/viewdoc/...

3) Moser, Kim & Mansour, Direct numerical simulation of turbulent channel flow up to Re_tau = 590. Physics of Fluids, 11(4), 1999.
https://cfd.spbstu.ru/agarbaruk/doc/1...

4) The complete set of statistical DNS data for turbulent channel flow:
http://turbulence.ices.utexas.edu/MKM...

5) J. Bredberg. On the wall boundary condition for turbulence models. Internal report 00/4, Chalmers University of Technology, Sweden, 2000.
http://www.tfd.chalmers.se/~lada/post...

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Disclaimer
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The methods, algorithms, equations, formulae, diagrams and explanations in this talk are for educational and demonstrative purposes only. They should never be used to analyse, design, accredit or validate real scientific / engineering / mathematical structures and flow systems. For such applications, appropriate trained, qualified and accredited (SQEP) engineers / scientists should be consulted along with the appropriate documentation, procedures and engineering standards. Furthermore, the information contained within this talk has not been verified, peer reviewed or checked in any way and is likely to contain several errors. It is therefore not appropriate to use this talk itself (or any of the algorithms, equations, formulae, diagrams and explanations contained within this talk) as an academic or technical reference. The reader should consult the original references and follow the verification and validation processes adopted by your company / institution when carrying out engineering calculations and analyses. Fluid Mechanics 101 and Dr. Aidan Wimshurst are not accountable or liable in any form for the use or misuse of the information contained in this talk beyond the specific educational and demonstrative purposes for which it was intended.