How to specify k & epsilon?

January 19, 2005, 23:18

I am using k & epsilon model to simulate. How can I specify them? I use the eqation in the help document. k=1.5*(Uave*I)^2 epsilon=0.09^0.75*k^1.5/(0.07*Dh) Where Uave is average velocity, and Dh is hydralic diameter. But when I calculate, the k and epsilon residuals are highly fluctuant. Is there any method to deal with this problem? Thanks a lot

January 20, 2005, 04:05

You can try to modify the under relation factors, so that the solution can converge with a certain stability. In particular, you can lower the factors of about 50%. Riccardo

January 19, 2005, 23:18	How to specify k & epsilon?	#1
Jen Guest Posts: n/a	I am using k & epsilon model to simulate. How can I specify them? I use the eqation in the help document. k=1.5(UaveI)^2 epsilon=0.09^0.75k^1.5/(0.07Dh) Where Uave is average velocity, and Dh is hydralic diameter. But when I calculate, the k and epsilon residuals are highly fluctuant. Is there any method to deal with this problem? Thanks a lot

January 20, 2005, 04:05	Re: How to specify k & epsilon?	#2
Riccardo Buccolieri Guest Posts: n/a	You can try to modify the under relation factors, so that the solution can converge with a certain stability. In particular, you can lower the factors of about 50%. Riccardo

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