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-   -   Difference between oodles and "oodLagrangianFoam (http://www.cfd-online.com/Forums/openfoam-solving/63830-difference-between-oodles-oodlagrangianfoam.html)

flying April 21, 2009 08:10

Difference between oodles and "oodLagrangianFoam
 
Dear all:

I have made a solver of oodLagrangianFoam as icoFoam.

Now everything is ok except there is some difference between the result of "oodles" and "oodLagrangianFoam" when I only compute the flowfield. The difference is as the below lines:
oodLagrangianFoam

Starting time loop

Reading/calculating field UMean

Reading/calculating field pMean

Reading/calculating field UPrime2Mean

Reading/calculating field pPrime2Mean

Time = 1e-06

Courant Number mean: 0 max: 0.000871632
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 3.81505e-09, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 1.25195e-08, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 1.12197e-08, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.0453494, No Iterations 166
time step continuity errors : sum local = 2.53027e-07, global = -7.12624e-10, cumulative = -7.12624e-10
DICPCG: Solving for p, Initial residual = 0.0592759, Final residual = 9.81774e-07, No Iterations 182
time step continuity errors : sum local = 1.52743e-09, global = -2.03866e-12, cumulative = -7.14663e-10
ExecutionTime = 5.06 s ClockTime = 5 s

Calculating averages

Time = 2e-06

Courant Number mean: 0.000147711 max: 0.00344423
DILUPBiCG: Solving for Ux, Initial residual = 0.347412, Final residual = 1.50109e-07, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.407471, Final residual = 3.01995e-07, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.33329, Final residual = 4.12535e-07, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.0651253, Final residual = 0.00246889, No Iterations 162
time step continuity errors : sum local = 2.76872e-06, global = 2.88385e-08, cumulative = 2.81238e-08

oodles:

Time = 1e-06

Courant Number mean: 0 max: 0.000871632
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 3.81893e-09, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 1.14863e-08, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 1.09542e-08, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.045263, No Iterations 166
time step continuity errors : sum local = 2.52412e-07, global = -7.21685e-10, cumulative = -7.21685e-10
DICPCG: Solving for p, Initial residual = 0.0592747, Final residual = 9.81467e-07, No Iterations 182
time step continuity errors : sum local = 1.52615e-09, global = -2.03287e-12, cumulative = -7.23718e-10
ExecutionTime = 5.16 s ClockTime = 6 s

Calculating averages

Time = 2e-06

Courant Number mean: 0.000147626 max: 0.00344243
DILUPBiCG: Solving for Ux, Initial residual = 0.347412, Final residual = 1.49969e-07, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.407459, Final residual = 3.01704e-07, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.33329, Final residual = 4.12142e-07, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.0651229, Final residual = 0.0024665, No Iterations 162
time step continuity errors : sum local = 2.76459e-06, global = 2.8777e-08, cumulative = 2.80532e-08
DICPCG: Solving for p, Initial residual = 0.137205, Final residual = 8.74102e-07, No Iterations 184
time step continuity errors : sum local = 5.32549e-10, global = 1.23002e-12, cumulative = 2.80545e-08
ExecutionTime = 8.61 s ClockTime = 9 s

Ps: In fact I have tried to make everything is the same, but I don't know how the difference comes out.

Do you have some idea about it?

Thanks!

Xinguang Cui

matejfor April 22, 2009 12:32

Maybe I'm completely blind, but I could not see any difference. I mean there are some minor number difference, but ...

what are you BC? any turbulence forcing, or is there deterministic inlet, which gives always the same numbers to crunch? do you run the code parallel?

good luck
matej

flying April 23, 2009 13:55

Thanks for your reply!

You are right, but it should be equal each other.In fact, BC is the same. The inlet condition is also sameI didn't run it in the parallel way.


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