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vivek Kumar March 30, 2006 13:12

V2f Model implementation
 
I am implementing V2f model using segregated approach.I am facing some difficulty. What is the boundary condition for epsilon?At present I am applying(epsilon=2*mu*k1/(y1^2) Another problem I am getting is that v2 is not reaching its peak no matter what initial condition I use.It always remains at a very low value in the entire domain. Also in what range the elliptic function(f) should lie. At present I am solving for flat plate.


turb April 7, 2006 00:41

Re: V2f Model implementation
 
Hi Kumar,

I am also trying to implement v2f for flat plate at Re>1000000.

At which AOA are you planing to run your simulations?

I was still getting divergent solutions a while ago. Things look to get better now.

As you, I also have doubts about boundary conditions, and details of implementations that cannot be found in papers...

Which of the variant of v2f are you using?

Which code? (are you developing your own?

Which boundary conditions for f in inlet and outlet boundaries? (at walls it is zero, but dont know about other boundaries... I am trying to set zero at every boundary...)

For epsilon at walls I am using zero gradient.

Maybe we can exchange experiences here...

Vivek Kumar April 8, 2006 11:27

Re: V2f Model implementation
 
I have tried to implement Durbin's original model using my own code.The epsilon boundary condition at the wall is 2*nu*k1/(y1^2), while f at the wall is -20*nuv2/(y^4*k1) (the asymptotic value mentioned in durbin's paper).I have used neumann b.c at the inlet and outlet for flat plate,channel flow and bfs.I have solved v2f model for flat plate, 2-Dchannel and bfs.In case of bfs I am not getting convergence.Abs(uold-unew)/dt is oscillating around 0.004.flat plate and channel flow results seems to be fine.In case of bfs reattachment length is coming around 6.18 which also seems fine.But I am not sure abt the values.At present I am solving for plane jet.....


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