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-   -   Boundary conditions for the LRR model (http://www.cfd-online.com/Forums/openfoam-solving/60221-boundary-conditions-lrr-model.html)

andimb May 9, 2006 11:30

Hi! How do I define the bou
 
Hi!

How do I define the boundary conditions for the LRR turbulence model at an inlet, an outlet and a wall?

Is this right?
inlet:
R_ii = 2/3*k
R_ij = 0 i<>j
outlet:
zero gradient
wall:
zero gradient

Thanks
Andreas

s.m October 16, 2013 03:43

Quote:

Originally Posted by andimb (Post 183422)
Hi!

How do I define the boundary conditions for the LRR turbulence model at an inlet, an outlet and a wall?

Is this right?
inlet:
R_ii = 2/3*k
R_ij = 0 i<>j
outlet:
zero gradient
wall:
zero gradient

Thanks
Andreas

Hi Andreas
i am simulatinf the flow over an airfoil, i use simpleFoam and LRR turbulence model, but my simulation with this model diverged, i don't know why!
did you understand How to define the boundary conditions for the LRR turbulence model at inlet &outlet &wall?

bgraves November 1, 2013 15:55

Hi S.M

if your simulation is diverging, what you can try is to run k-epsilon for 1000 iterations, then run the R command in terminal. Then go to RAS properties and change k-epsilon to LRR.

At the wall with a wall resolved grid the Reynolds stress tensor should be zero. At the inlet I use fixedValue and zeroGradient at the outlet.

Hope this helps,
-Ben

s.m November 4, 2013 05:42

Quote:

Originally Posted by bgraves (Post 460167)
Hi S.M

if your simulation is diverging, what you can try is to run k-epsilon for 1000 iterations, then run the R command in terminal. Then go to RAS properties and change k-epsilon to LRR.

At the wall with a wall resolved grid the Reynolds stress tensor should be zero. At the inlet I use fixedValue and zeroGradient at the outlet.

Hope this helps,
-Ben

Ok, i 'll do it Ben.
Thank you very much:)


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