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- - **Lien cubic low Re model**
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Hi users:
Can anyone here Hi users:
Can anyone here tell me the source paper of lien cubic low Re model in openfoam? Is it two-equation model or three-equation model in the foam? By that, I mean if the transport equation for the second invariant of the Reynolds Stress A2 (aijaij) is solved? I found three papers as follows: Craft, T.J., Launder, B.E., Suga, K., 1996. Development and application of a cubic eddy-viscosity model of turbulence. International Journal of Heat and Fluid Flow 17, 108-115. Craft, T.J., Launder, B.E., Suga, K., 1997. Prediction of turbulent transitional phenomena with a nonlinear eddy-viscosity model. International Journal of Heat and Fluid Flow 18, 15-28. Chen, W.L., Lien, F.S., Leschziner, M.A., 1998. Non-linear eddy-viscosity modeling of transitional boundary layers pertinent to turbomachine aerodyanamics. International Journal of Heat and Fluid Flow 19, 297-306. The source code seems different from these papers. Thanks a lot. Ning |

Cubic Lein modelHi Ning,
I saw your message kind of 2 years later therefore you might have solved your problem already. Nevertheless I would like to answer to you for somebody else taking a look to your question. I don't know about OpenFoam but in Star-CCM+ the references is: 1) Lien, F.S., Chen, W.L., and Leschziner, M.A. 1996. “Low-Reynolds number eddy-viscosity modelling based on non-linear stress-strain/vorticity relations”, Proc. 3rd Symp. on Eng. Turbulence Modelling and Measurements, 27-29 May, Crete, Greece. It is a quite difficult paper to find though. You might refer also to: Lien, Leschziner, (1995), ASME Paper 95-CTP-80. Nevertheless in addition, the Lien model is a two equation model, just you mean the second (quadratic) and third (cubic) order terms are introduced or not in the turbulent viscosity definition. The Lien model contains both quadratic and cubic terms, but you can easily neglect them, setting the coefficients to zero in case you don't really need them, to solve simple geometries as for straight fully developed pipes or channel for example. Hope this helps, Marco. |

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