rhoPimpleFoam for Inviscid Simulation
 

I am trying to simulate a Combustion Chamber (only flow simulation; no combustion) with 10 outlets.

I wrote a custom BC using groovyBC for inlet (which is burn surface) - Mass generation which changes with time.

10 Outlets - Mass Outflow profile. All the walls are inviscid.

First I am trying to get a steady state solution of certain chamber pressure - Mass generation is equal to net mass outflow of 10 outlets..

Since the flow velocity is low subsonic (<0.2), i am using rhoPimpleFoam.

As the simulation progresses, the rhoMax keeps on increases and rhoMin keeps in decreasing and also the velocity. The simulation blows saying Maximum number of iteration exceeded.

Whether rhoPimpleFoam can be used to simulated Inviscid simulation?

I have attached the boundary condition and solver setup

Thanks
KGN

Attachment 40937

Attachment 40938

Attachment 40939

1. I am using Mass flow Rate boundary condition at Inlet and Outlet. Is it a problem?
2. Whether rhoPimpleFoam can solve Inviscid Simulation?
3. I am able to solve the simulation using rhoCentralFoam, but it takes a long time. Max Co i can use is 0.55. Is there a way to increase the Co number? Also rhoCentralFoam is true transient solver?
I guess the problem is with the Boundary condition. Both at inlet and outlet mass flow rate is specified. For pressure zero gradient is used. So this is creating the problem?




time step continuity errors : sum local = 6.16642e-08, global = -6.09083e-08, cumulative = -4.11783e-08
rho max/min : 25 8.04696
PIMPLE: iteration 2
smoothSolver: Solving for Ux, Initial residual = 0.000154991, Final residual = 8.7961e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 0.000494649, Final residual = 4.37157e-07, No Iterations 2
smoothSolver: Solving for Uz, Initial residual = 0.00055955, Final residual = 1.41411e-06, No Iterations 2
smoothSolver: Solving for e, Initial residual = 0.0107836, Final residual = 3.66265e-07, No Iterations 2
[0]
[0]
[0] --> FOAM FATAL ERROR:
[0] Maximum number of iterations exceeded
[0]
[0] From function thermo<Thermo, Type>::T(scalar f, scalar T0, scalar (thermo<Thermo, Type>::*F)(const scalar) const, scalar (thermo<Thermo, Type>::*dFdT)(const scalar) const, scalar (thermo<Thermo, Type>::*limit)(const scalar) const) const
[0] in file /home/rcdt/OpenFOAM/OpenFOAM-2.3.0/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.
[0]
FOAM parallel run aborting
[0]
[0] #0 Foam::error::printStack(Foam::Ostream&) in "/home/rcdt/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #1 Foam::error::abort() in "/home/rcdt/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #2 Foam::species::thermo<Foam::hConstThermo<Foam::per fectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::T(double, double, double, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double) const) const in "/home/rcdt/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
[0] #3 Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam::perfectGas<Foa m::specie> >, Foam::sensibleInternalEnergy> > > >::calculate() in "/home/rcdt/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"

Is there any method to set relaxation factor and relaxation tolerance ?

Any reply?

I tried with different settings of relaxation factor and relaxation residual, but still the simulation blows after few iterations.