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-   -   Unstable BuoyantBoussinesqSimpleFoam (https://www.cfd-online.com/Forums/openfoam-solving/126951-unstable-buoyantboussinesqsimplefoam.html)

ozzythewise November 29, 2013 12:13

Unstable BuoyantBoussinesqSimpleFoam
 
Hello all,

I'm trying to solve a relatively simple steady-state heat transfer problem in a duct but I cannot get my solution to converge. I am using the BuoyantBoussinesqSimpleFoam solver. I've been able to get a converged solution using simpleFoam without heat transfer. I have attached a link to my case below.

Any help would be greatly appreciated. Thanks!

Link to case: http://www.speedyshare.com/hXuEP/R1-...-PR1.84.tar.gz

ozzythewise November 29, 2013 12:46

Something to add to this is that there is clearly something wrong with my calculation of p_rgh, as it does not converge in each iteration. See output below:

Code:

Time = 8

DILUPBiCG:  Solving for Ux, Initial residual = 0.0164766, Final residual = 4.00432e-06, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.0539052, Final residual = 1.43627e-05, No Iterations 1
DILUPBiCG:  Solving for T, Initial residual = 0.00648091, Final residual = 2.69615e-08, No Iterations 1
DICPCG:  Solving for p_rgh, Initial residual = 0.0574019, Final residual = 0.169052, No Iterations 1001
time step continuity errors : sum local = 0.473557, global = -0.000529186, cumulative = -0.00322094
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000177516, Final residual = 7.06656e-08, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.00285575, Final residual = 1.46059e-06, No Iterations 1
ExecutionTime = 54.25 s  ClockTime = 54 s



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