shipman |
March 21, 2014 05:55 |
Divergence problem in interpasechangefoam
3 Attachment(s)
Hi to all,
I am trying to simulate cavitation inside of nozzle. It is turbulent flow, used RNG k-epsilon turbulence model. My nozzle shape is attached. Upside is inlet (wider one) down side is outlet. I am using interphasechangeFoam ver2.1.1. I have just done following modification in U.Eqn to decrease the calculate nut as indicated in the paper of Coutier Delgosha (2003).
Code:
dimensionedScalar rhoUnit("rhoUnit", dimDensity, 1.0);
surfaceScalarField muEff
(
"muEff",
twoPhaseProperties->muf()
+ fvc::interpolate((Foam::pow((0.017-rho/rhoUnit),5)/Foam::pow((0.017-998),5)*(998-0.017)+ 0.017)*rho*turbulence->nut())
);
I set the my BCs:
0/U
inlet ==> FixedValue
HTML Code:
outlet= intletOutlet and tried pressureInletOutletVelocity;
0/p_rgh
HTML Code:
inlet ==> zeroGradient
Outlet==> fixedValues ==>1e5, 1e4...0 (gradully decreased until 0)
and also for outlet i tried: fixedMeanValue
0/k-epsilon
HTML Code:
inlet ==>fixedValue
outlet ==> tried fixedValue and inletOutlet
wall ==>tried epsilonWallFunction/kqRWallFunction and zerogradient
0/nut
HTML Code:
inlet/outlet ==>calculated
wall==>nutkWallFunction
fvschemes
HTML Code:
divSchemes
div(rhoPhi,U) Gauss linear;
div(phi,epsilon) Gauss upwind;
div(phi,k) Gauss upwind;
div(phi,alpha) Gauss vanLeer;
div(phirb,alpha) Gauss interfaceCompression;
laplacianSchemes
{
default Gauss linear corrected;
}
snGradSchemes
{
default none;
snGrad(pd) limited 0.5;
snGrad(rho) limited 0.5;
snGrad(alpha1) limited 0.5;
}
fluxRequired
{
default none;
p_rgh;
pcorr;
alpha1;
}
fv.solution==>everything is same with tutorial only added:
HTML Code:
relaxationFactors
{
fields
{
}
equations
{
"U.*" 0.7;
"k.*" 0.5;
"epsilon.*" 0.5;
"p_rgh.*" 0.3;
}
==>>maxCo 0.5; I set deltaT as 10-7, 10-8.
Although i tried different BCS as indicated above always deltaT reached very low valuse and gave divergence floating point error as follows:
HTML Code:
GAMG: Solving for p_rgh, Initial residual = 9.10213e-09, Final residual = 9.10213e-09, No Iterations 0
GAMG: Solving for p_rgh, Initial residual = 9.10213e-09, Final residual = 9.10213e-09, No Iterations 0
time step continuity errors : sum local = 2.80061e+06, global = -4.94029e-10, cumulative = 0.00804153
GAMG: Solving for p_rgh, Initial residual = 1.20034e-08, Final residual = 9.50047e-10, No Iterations 1
GAMGPCG: Solving for p_rgh, Initial residual = 4.32284e-15, Final residual = 4.32284e-15, No Iterations 0
time step continuity errors : sum local = 994878, global = -2.11248e-10, cumulative = 0.00804153
PIMPLE: not converged within 50 iterations
ExecutionTime = 1974.23 s ClockTime = 2002 s
Courant Number mean: 6.58573e+06 max: 2.47105e+13
deltaT = 2.17834e-30
--> FOAM Warning :
From function Time::operator++()
in file db/Time/Time.C at line 1010
Increased the timePrecision from 8 to 9 to distinguish between timeNames at time 6.97175e-05
Time = 6.97175051e-05
[11] #0 Foam::error::printStack(Foam::Ostream&)[3] #0 Foam::error::printStack(Foam::Ostream&)[7] #0 Foam::error::printStack(Foam::Ostream&)[6] #0 Foam::error::printStack(Foam::Ostream&)[10] #0 Foam::error::printStack(Foam::Ostream&)[9] #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[3] #1 Foam::sigFpe::sigHandler(int)[2] #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[11] #1 Foam::sigFpe::sigHandler(int)[4] #0 Foam::error::printStack(Foam::Ostream&)[5] #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[9] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[10] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #2 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[2] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[3] #2 [0] #0 Foam::error::printStack(Foam::Ostream&)[1] #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[4] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[5] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[9] #2 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[11] #2 in "/lib/libc.so.6"
[3] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[10] #2 [8] #0 Foam::error::printStack(Foam::Ostream&) in "/lib/libc.so.6"
[7] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[6] #1 Foam::sigFpe::sigHandler(int) in "/lib/libc.so.6"
[11] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[2] #2 in "/lib/libc.so.6"
[9] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libO in "/opt/openfoam211/platforms/penFOAM.so"
[0] #1 linux64GccDPOpt/lib/libOpenFOAM.so"
Foam::sigFpe::sigHandler(int)[1] #1 Foam::sigFpe::sigHandler(int)
in "/lib/libc.so.6"
[10] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[5] #2
in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[4] #2
in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[8] #1 Foam::sigFpe::sigHandler(int) in "/lib/libc.so.6"
[2] #3
[7] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[7] #4 [3] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[3] #4 [11] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[11] #4 in "/lib/libc.so.6"
[5] #3 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[6] #2 in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[1] #2 in "/lib/ in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #2 libc.so.6"
[4] #3
[10] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[10] #4
in "/lib/libc.so.6"
[1] #3
in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[8] #2 in "/lib/libc.so.6"
[0] #3 [2] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[2] #4 [11] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[11] #5 [9] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[9] #4
in "/lib/libc.so.6"
[6] #3 [3] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[3] #5
[4] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[4] #4 [7] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[7] #5 in "/lib/libc.so.6"
[8] #3
[5] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[5] #4
[9] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[9] #5 [11] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[11] #6 __libc_start_main[0] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[0] #4 [1] in "/home/yusuke/OpenFOAM/yusuke-2.1[3] in "/home/yusuke/OpenFOAM/yusuke.1/platforms/linux64GccDPOpt/bin/RNGinterP-2.1.1/platforms/linux64GccDPOpt/bin/RhaseChangeFoam"
NGinterPhaseChangeFoam"
[1] #4 [3] #6 __libc_start_main
[2] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[2] #5
[6] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[6] #4 [10] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[10] #5 in "/lib/libc.so.6"
[11] #7
[7] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[7] #6 __libc_start_main
in "/lib/libc.so.6"
[3] #7
[4] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[4] #5 [9] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[9] #6 __libc_start_main[6] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[6] #5 in "/lib/libc.so.6"
[7] #7
[1] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[1] #5 [2] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[2] #6 __libc_start_main
[10] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[10] #6 __libc_start_main[5] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[5] #5
[8] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[8] #4
in "/lib/libc.so.6"
[2] #7
[11] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[VENUS:26554] *** Process received signal ***
[VENUS:26554] Signal: Floating point exception (8)
[VENUS:26554] Signal code: (-6)
[VENUS:26554] Failing at address: 0x3e8000067ba
[VENUS:26554] [ 0] /lib/libc.so.6(+0x33af0) [0x7f17f47d3af0]
[VENUS:26554] [ 1] /lib/libc.so.6(gsignal+0x35) [0x7f17f47d3a75]
[VENUS:26554] [ 2] /lib/libc.so.6(+0x33af0) [0x7f17f47d3af0]
[VENUS:26554] [ 3] RNGinterPhaseChangeFoam() [0x4a8442]
[VENUS:26554] [ 4] RNGinterPhaseChangeFoam() [0x4b74fd]
[VENUS:26554] [ 5] RNGinterPhaseChangeFoam() [0x435358]
[VENUS:26554] [ 6] /lib/libc.so.6(__libc_start_main+0xfd) [0x7f17f47bec4d]
[VENUS:26554] [ 7] RNGinterPhaseChangeFoam() [0x42b849]
[VENUS:26554] *** End of error message ***
in "/lib/libc.so.6"
[10] #7 [0] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[0] #5 in "/lib/libc.so.6"
[9] #7 [3] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[VENUS:26546] *** Process received signal ***
[VENUS:26546] Signal: Floating point exception (8)
[VENUS:26546] Signal code: (-6)
[VENUS:26546] Failing at address: 0x3e8000067b2
[VENUS:26546] [ 0] /lib/libc.so.6(+0x33af0) [0x7ff896532af0]
[VENUS:26546] [ 1] /lib/libc.so.6(gsignal+0x35) [0x7ff896532a75]
[VENUS:26546] [ 2] /lib/libc.so.6(+0x33af0) [0x7ff896532af0]
[VENUS:26546] [ 3] RNGinterPhaseChangeFoam() [0x4a8483]
[VENUS:26546] [ 4] RNGinterPhaseChangeFoam() [0x4b74fd]
[VENUS:26546] [ 5] RNGinterPhaseChangeFoam() [0x435358]
[VENUS:26546] [ 6] /lib/libc.so.6(__libc_start_main+0xfd) [0x7ff89651dc4d]
[VENUS:26546] [ 7] RNGinterPhaseChangeFoam() [0x42b849]
[VENUS:26546] *** End of error message ***
[1] in "/home/yusuke/OpenFOAM/yusuke-2.1.1/platforms/linux64GccDPOpt/bin/RNGinterPhaseChangeFoam"
[1] #6 __libc_start_main
And, finally when i viewed the result of P_rgh and U as you can see left side of the small throat entrance always obtained strange high velocity and very high inlet pressure.
I dont know what i can do .Please can someone guide and tell me some new ways..
Thanks in advance.
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