6 subdomain OK--------8 subdomain wrong?
 

Hi, dear Formers,
I am countering a problem,
I am runing turbDyMFoam on GGI.

When I use a coarser 2D mesh of about 60000 cells, decomposition to 6 or 8 subdomains are both OK.
Then I increase the same geometry to about 90000 cells, only 6 subdomains is OK, when I decompose to 8 subdomains:

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Reading field rAU if present

Starting time loop
Courant Number mean: 0 max: 0.00695905 velocity magnitude: 10
Time = 7e-05
--> FOAM Warning :
From function min(const UList<Type>&)
in file lnInclude/FieldFunctions.C at line 342
empty field, returning zero
Evaluation of GGI weighting factors:
Largest slave weighting factor correction : 5.1734e-07 average: 5.17339e-07
Largest master weighting factor correction: 5.55112e-16 average: 1.51588e-16
--> FOAM Warning :
From function min(const UList<Type>&)
in file lnInclude/FieldFunctions.C at line 342
empty field, returning zero
BiCGStab: Solving for Ux, Initial residual = 1, Final residual = 3.57257e-15, No Iterations 2
BiCGStab: Solving for Uy, Initial residual = 1, Final residual = 5.81369e-12, No Iterations 2
PCG: Solving for p, Initial residual = 1, Final residual = 8.98239e-11, No Iterations 1176
PCG: Solving for p, Initial residual = 0.0342773, Final residual = 9.52116e-11, No Iterations 790
time step continuity errors : sum local = 5.54927e-13, global = 2.7808e-15, cumulative = 2.7808e-15
PCG: Solving for p, Initial residual = 0.00224453, Final residual = 9.47194e-11, No Iterations 738
PCG: Solving for p, Initial residual = 0.000208696, Final residual = 9.87691e-11, No Iterations 665
time step continuity errors : sum local = 6.00154e-13, global = -2.09637e-15, cumulative = 6.84426e-16
PCG: Solving for p, Initial residual = 2.13993e-05, Final residual = 9.74497e-11, No Iterations 505
PCG: Solving for p, Initial residual = 2.56864e-06, Final residual = 9.93453e-11, No Iterations 432
time step continuity errors : sum local = 6.03417e-13, global = 1.89596e-15, cumulative = 2.58039e-15
PCG: Solving for p, Initial residual = 3.2933e-07, Final residual = 9.43981e-11, No Iterations 407
PCG: Solving for p, Initial residual = 4.86326e-08, Final residual = 9.75431e-11, No Iterations 344
time step continuity errors : sum local = 5.92464e-13, global = -3.66527e-15, cumulative = -1.08488e-15
BiCGStab: Solving for epsilon, Initial residual = 0.995295, Final residual = 6.98742e-11, No Iterations 127
BiCGStab: Solving for k, Initial residual = 1, Final residual = 4.99912e-11, No Iterations 9
ExecutionTime = 10.18 s ClockTime = 11 s
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I have look through FieldFunctions.C, but didn't get an idea.
Can you give me some hints on what kind of problem this would be like?
and I can check that respect.

Best Regards
yuhai