[Thomas pan]

Hi,

I use transonicMRFDyMFoam in DensityBasedTurbo to simulate NASA rotor 37.The steady axial rotor (with MRF) test case (Axial_Rotor_MRF) runs very well. But when I increase the angular velocity to 1799.929rad/s(17188.7RPM) the solution diverges.when I put the angular velocity to zero,the problem also exists,The output is(the log file):

Time = 8

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
rho L2 Residual: 5.16689
rho LInf Residual: 7.36605

DILUPBiCG: Solving for omega, Initial residual = 0.000861369, Final residual = 4.21693e-09, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.046028, Final residual = 5.57907e-10, No Iterations 2

ExecutionTime = 8.31 s

MassFlows: inlet_0 = 15.1579
MassFlows: outlet_0 = 11.1839
Averages of p : inlet_0 = 86982.6 outlet_0 = 90000
Averages of rho : inlet_0 = 1.08072 outlet_0 = 1.10715
Averages of T : inlet_0 = 279.745 outlet_0 = 282.553
Averages of U : inlet_0 = (0 0 210) outlet_0 = (0.0410341 -0.00350159 153.843)
Mach number min = 0.572932 max = 5.92444

Time = 9

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
bounding rho, min: -5.81025 max: 7.60996 average: 0.99375
bounding rhoE, min: -8.46808e+06 max: 530434 average: 216250
bounding U max: 2659.85
bounding h, min: -689976 max: 1.41092e+06 average: 280809
rho L2 Residual: 5.14218
rho LInf Residual: 7.24862

DILUPBiCG: Solving for omega, Initial residual = 0.000900813, Final residual = 4.53341e-09, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0405624, Final residual = 5.64841e-10, No Iterations 2

ExecutionTime = 9.21 s

MassFlows: inlet_0 = 15.2526
MassFlows: outlet_0 = 11.0168
Averages of p : inlet_0 = 87714.9 outlet_0 = 90000
Averages of rho : inlet_0 = 1.08703 outlet_0 = 1.10491
Averages of T : inlet_0 = 280.462 outlet_0 = 283.128
Averages of U : inlet_0 = (0 0 210) outlet_0 = (0.0529771 -0.00329286 151.972)
Mach number min = 0.560413 max = 5.98648

Time = 10

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
bounding rho, min: -0.980468 max: 7.69712 average: 0.993911
bounding rhoE, min: -1.2419e+06 max: 3.62038e+06 average: 216681
bounding U max: 4430.19
bounding h, min: -640162 max: 1.1924e+07 average: 280843
rho L2 Residual: 5.65076
rho LInf Residual: 8.0581

DILUPBiCG: Solving for omega, Initial residual = 0.000955905, Final residual = 4.85834e-09, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0362823, Final residual = 5.84462e-10, No Iterations 2

ExecutionTime = 10.07 s

MassFlows: inlet_0 = 15.3416
MassFlows: outlet_0 = 10.8608
Averages of p : inlet_0 = 88402.8 outlet_0 = 90000
Averages of rho : inlet_0 = 1.09292 outlet_0 = 1.1026
Averages of T : inlet_0 = 281.135 outlet_0 = 283.722
Averages of U : inlet_0 = (0 0 210) outlet_0 = (0.0662899 -0.00263111 150.259)
Mach number min = 0.43905 max = 6.62729

Time = 11

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
bounding rho, min: -1.24433 max: 8.80987 average: 0.994042
bounding rhoE, min: -634231 max: 2.23324e+06 average: 217049
bounding U max: 8869.66
bounding h, min: -681399 max: 6.57337e+06 average: 280823

From function specieThermo<thermo>::T(scalar f, scalar T0, scalar (specieThermo<thermo>::*F)(const scalar) const, scalar (specieThermo<thermo>::*dFdT)(const scalar) const) const
in file /home/pjc/OpenFOAM/OpenFOAM-1.6-ext/src/thermophysicalModels/specie/lnInclude/specieThermoI.H at line 73
Maximum number of iterations exceeded. Rescue by HJ

From function specieThermo<thermo>::T(scalar f, scalar T0, scalar (specieThermo<thermo>::*F)(const scalar) const, scalar (specieThermo<thermo>::*dFdT)(const scalar) const) const
in file /home/pjc/OpenFOAM/OpenFOAM-1.6-ext/src/thermophysicalModels/specie/lnInclude/specieThermoI.H at line 73
Maximum number of iterations exceeded. Rescue by HJ
rho L2 Residual: 5.62427
rho LInf Residual: 8.12631

DILUPBiCG: Solving for omega, Initial residual = 0.00102054, Final residual = 5.30412e-09, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0328314, Final residual = 6.16675e-10, No Iterations 2

ExecutionTime = 10.96 s

MassFlows: inlet_0 = 15.4248
MassFlows: outlet_0 = 10.7161
Averages of p : inlet_0 = 89042 outlet_0 = 90000
Averages of rho : inlet_0 = 1.09837 outlet_0 = 1.10024
Averages of T : inlet_0 = 281.765 outlet_0 = 284.331
Averages of U : inlet_0 = (0 0 210) outlet_0 = (0.0808756 -0.00145528 148.699)
Mach number min = 0.544759 max = 9.16173

Time = 12

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
bounding rho, min: -255.736 max: 9.39452 average: 0.992603
bounding rhoE, min: -1.40862e+08 max: 2.28263e+06 average: 216533
bounding U max: 179979
bounding h, min: -640549 max: 3.72345e+06 average: 280795

From function specieThermo<thermo>::T(scalar f, scalar T0, scalar (specieThermo<thermo>::*F)(const scalar) const, scalar (specieThermo<thermo>::*dFdT)(const scalar) const) const
in file /home/pjc/OpenFOAM/OpenFOAM-1.6-ext/src/thermophysicalModels/specie/lnInclude/specieThermoI.H at line 73
Maximum number of iterations exceeded. Rescue by HJ

From function specieThermo<thermo>::T(scalar f, scalar T0, scalar (specieThermo<thermo>::*F)(const scalar) const, scalar (specieThermo<thermo>::*dFdT)(const scalar) const) const
in file /home/pjc/OpenFOAM/OpenFOAM-1.6-ext/src/thermophysicalModels/specie/lnInclude/specieThermoI.H at line 73
Maximum number of iterations exceeded. Rescue by HJ
rho L2 Residual: 5.68874
rho LInf Residual: 8.19002

DILUPBiCG: Solving for omega, Initial residual = 0.00110804, Final residual = 5.82807e-09, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0300058, Final residual = 6.62385e-10, No Iterations 2

My ICs and BCs:

for pressure (p file)
-------------------------
internalField uniform 80000.0

inlet_0
{
type zeroGradient;
}

outlet_0
{
type fixedValue;
value uniform 90000.0;
}

for velocity (u file)
-----------------------


internalField uniform (0 50.0 170.0);

boundaryField
{
inlet_0
{
type temperatureDirectedInletVelocity;
inletDirection uniform (0 0 1); // Direction of absolute velocity in cartesian coordinates
phi phi; // just needed in compressible case to check dimensions
T T; // name of the static temperature field
T0 uniform 293.0; // value of the total temperature
cylindricalCS no; // specifies if inletDirection is in cartesian or cylindrical coordinates
omega (0 0 0); // angular velocity
value uniform (0 0 210); // Initial Value
}

for temperature (T file)
-----------------------------
internalField uniform 280.0;

inlet_0
{
type isentropicTotalTemperature;
p p; // name of static pressure field
T0 uniform 293.0; // absolute total temperature field
p0 uniform 101325; // absolute total presure field
value uniform 280; // initial value
}

outlet_0
{
type zeroGradient;
}

MRFZones:
cellRegion0
{
// Fixed patches (by default they 'move' with the MRF zone)
nonRotatingPatches (inlet_0 outlet_0 passageSidesUpper_0 passageSidesLower_0);

origin origin [0 1 0 0 0 0 0] (0 0 0);
axis axis [0 0 0 0 0 0 0] (0 0 1);
omega omega [0 0 -1 0 0 0 0] 1799.929;
}

The case setting is allmost the same as the test case Axial_Rotor_MRF,just put the angular velocity as Numeca setting(it is perfectly running with Numeca).Who can give me some tips?I have tried all the mothod I can see.

[MK12]

I am trying to do the same thing (rotor 37, transonicMRFDyMFoam) , and suffering from the divergence.

Have you managed to get a good convergence??

[tom.opt]

Originally Posted by MK12

I am trying to do the same thing (rotor 37, transonicMRFDyMFoam) , and suffering from the divergence.

Have you managed to get a good convergence??

have you made any progress on this ? I'm also working on rotor 37 and having a hard time getting the boundary conditions right

[MK12]

Hi,

Unfortunately, I could not get any appropriate solution by openfoam for rotor 37.

Though I have tried transonicMRFDyMFoam and steadyCompressibleMRFFoam, they didn’t work well.

steadyCompressibleMRFFoam seems to be used for rotor 67 simulations in some Universities, but I am not sure these are really acceptable enough to be published in archival journals.

[tom.opt]

Originally Posted by MK12

Hi,

Unfortunately, I could not get any appropriate solution by openfoam for rotor 37.

Though I have tried transonicMRFDyMFoam and steadyCompressibleMRFFoam, they didn’t work well.

steadyCompressibleMRFFoam seems to be used for rotor 67 simulations in some Universities, but I am not sure these are really acceptable enough to be published in archival journals.

I am currently trying to use the steadyCompressibleMRFFoam with cyclicGGI boundaries and replicate what's been done on rotor 67 to rotor 37.
I will let you know how it goes