[coastal593]

Hi all,

I am attempting to simulate a free jet expansion through a pinhole from atmospheric pressure to very reduced pressure (on the order of milliTorr) using the dieselFoam solver (as I intend to incorporate sprays into this model quickly).

I am, however, failing to understand the boundary conditions to impose here. Ironically, I know how to do this with FLUENT though I'd much rather use OpenFOAM, as I've had great success with OpenFOAM especially in the area of multiphase flow.

My domain is simple: a patch associated with the pinhole and another patch associated with the wall. The remaining patches should be transmissive. The wall conditions are self-explanatory.

Could someone suggest the appropriate conditions in p and U for the transmissive and inlet boundaries? Any help would be much appreciated ... this is my first try at a sonic expansion in OpenFOAM.

Anthony

[coastal593]

Anyone have ideas here?

I have tried pressureInletVelocity at the inlet and pressureTransmissive at transmissive boundaries, to no avail. Any suggestions would be much appreciated.

[coastal593]

Well, I got some advice to look at sonicTurbFoam, which I did. I implemented by two BCs in this way:

inlet: fixedValue in p at 1466 (arbitrary value, but large in comparison to pressure in the box). zeroGradient in U

outlet: waveTransmissive in p with a fairly standard setup (taken from prism example). inletOutlet uniform (0 0 0) in U.

one thing to note here is my pressures are very low. the pressure in the box is ~ 1.466 Pa, whereas atmospheric pressure 101325.

pretty much everything in my dieselFoam solver is turned off except for a very basic spray injection ... this injection runs fine if i remove all the complicated BCs (static box).

upon running with these BCs, i get the same errors I've been getting with every attempt, which are indecipherable to me.

[0] #0 Foam::error::printStack(Foam:stream&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #1 Foam::sigFpe::sigFpeHandler(int) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #2 ?? in "/lib/libc.so.6"
[0] #3 Foam::sqrt(Foam::Field<double>&, Foam::UList<double> const&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #4 Foam::tmp<foam::geometricfield<double,> > Foam::sqrt<foam::fvpatchfield,>(Foam::tmp<foam::ge ometricfield<double,> > const&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[0] #5 main in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[0] #6 __libc_start_main in "/lib/libc.so.6"
[0] #7 Foam::regIOobject::readIfModified() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[enskog:22743] *** Process received signal ***
[enskog:22743] Signal: Floating point exception (8)
[enskog:22743] Signal code: (-6)
[enskog:22743] Failing at address: 0x3e8000058d7
[enskog:22743] [ 0] /lib/libc.so.6 [0x2b43827507d0]
[enskog:22743] [ 1] /lib/libc.so.6(gsignal+0x35) [0x2b4382750765]
[enskog:22743] [ 2] /lib/libc.so.6 [0x2b43827507d0]
[enskog:22743] [ 3] /home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so(_ZN4Foam 4sqrtERNS_5FieldIdEERKNS_5UListIdEE+0x2c) [0x2b4381a5359c]
[enskog:22743] [ 4] dieselFoam(_ZN4Foam4sqrtINS_12fvPatchFieldENS_7vol MeshEEENS_3tmpINS_14GeometricF ieldIdT_T0_EEEERKS8_+0x389) [0x44fac9]
[enskog:22743] [ 5] dieselFoam [0x418ae8]
[enskog:22743] [ 6] /lib/libc.so.6(__libc_start_main+0xf4) [0x2b438273cb44]
[enskog:22743] [ 7] dieselFoam(_ZN4Foam11regIOobject14readIfModifiedEv +0x1d1) [0x415a19]
[enskog:22743] *** End of error message ***

i get the same basic errors when running on 1 proc. any advice would be welcome.

[coastal593]

does anyone have any input on this error message? i'm now getting this at some point early in every single dieselFoam simulation I try (even stuff that used to work well ... now does this). i have recompmiled many times now ... still, to no avail. nothing is diverging ... nothing seems to be misbehaving at all before this happens.

the current example is another spray. this mesh and boundary conditions used to work just fine. they are (abbreviated ..., most things are turned off).

--fixed value of velocity on inlet to the simulation. uniform (0 0 0) on all other walls. for the atmospheric BCs i use fluxCorrectedVelocity uniform (0 0 0) (use uniform (0 0 0) as internal field)

--zeroGradient on temperature everywhere except velocity inlet and atmosphere BCs, where it is fixed at 295 (internalField 295 also)

--zeroGradient in pressure everywhere but the atmospheric BCs, where i use totalPressure uniform 101325 (atmospheric pressure, internalField 101325 also).

like i said pretty much everything (chemistry, most spray submodels) is turned off, and checkMesh says my mesh is fine.

if anyone has any ideas i would greatly appreciate your comments.

thanks for your time.

output from dieselFoam:

[...]

Courant Number mean: 1.77008e-07 max: 0.483701
deltaT = 2.56682e-09
Time = 8.97327e-08

Evolving Spray
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for O2, Initial residual = 8.5023e-06, Final residual = 1.65267e-07, No Iterations 1
DILUPBiCG: Solving for H2O, Initial residual = 3.86183e-06, Final residual = 8.32983e-08, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 1.41151e-05, Final residual = 2.28392e-07, No Iterations 1
DICPCG: Solving for p, Initial residual = 3.51184e-06, Final residual = 9.32434e-10, No Iterations 1
DICPCG: Solving for p, Initial residual = 9.12955e-09, Final residual = 2.16046e-12, No Iterations 1
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.18128e-16, global = -1.82731e-18, cumulative = -4.84755e-16
DILUPBiCG: Solving for O2, Initial residual = 2.17952e-06, Final residual = 4.7853e-08, No Iterations 1
DILUPBiCG: Solving for H2O, Initial residual = 2.12266e-07, Final residual = 2.12266e-07, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 8.75189e-07, Final residual = 8.75189e-07, No Iterations 0
DICPCG: Solving for p, Initial residual = 1.32598e-07, Final residual = 4.01637e-11, No Iterations 1
DICPCG: Solving for p, Initial residual = 6.26912e-10, Final residual = 6.26912e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.22608e-16, global = -1.79112e-18, cumulative = -4.86546e-16
DILUPBiCG: Solving for O2, Initial residual = 8.80391e-07, Final residual = 8.80391e-07, No Iterations 0
DILUPBiCG: Solving for H2O, Initial residual = 2.12271e-07, Final residual = 2.12271e-07, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 1.27078e-06, Final residual = 3.19839e-07, No Iterations 1
DICPCG: Solving for p, Initial residual = 9.7914e-08, Final residual = 3.29239e-11, No Iterations 1
DICPCG: Solving for p, Initial residual = 4.23888e-10, Final residual = 4.23888e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.17294e-16, global = -1.98257e-18, cumulative = -4.88529e-16

Number of parcels in system | 34
Injected liquid mass....... | 9.063e-08 mg
Liquid Mass in system...... | 9.06299e-08 mg
SMD, Dmax.................. | 2.50955 mu, 5.24868 mu
Added gas mass = 3.43146e-06 mg
Evaporation Continuity Error| 3.43146e-06 mg
ExecutionTime = 5065.38 s ClockTime = 5066 s

Courant Number mean: 1.82124e-07 max: 0.483656
deltaT = 2.56682e-09
Time = 9.22995e-08

Evolving Spray
Solving chemistry
[1] #0 Foam::error::printStack(Foam:stream&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[1] #1 Foam::sigFpe::sigFpeHandler(int) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[1] #2 ?? in "/lib/libc.so.6"
[1] #3 Foam::sqrt(Foam::Field<double>&, Foam::UList<double> const&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
[1] #4 Foam::tmp<foam::geometricfield<double,> > Foam::sqrt<foam::fvpatchfield,>(Foam::tmp<foam::ge ometricfield<double,> > const&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[1] #5 main in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[1] #6 __libc_start_main in "/lib/libc.so.6"
[1] #7 Foam::regIOobject::readIfModified() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[enskog:14109] *** Process received signal ***
[enskog:14109] Signal: Floating point exception (8)
[enskog:14109] Signal code: (-6)
[enskog:14109] Failing at address: 0x3e80000371d
[enskog:14109] [ 0] /lib/libc.so.6 [0x2ab2d3b297d0]
[enskog:14109] [ 1] /lib/libc.so.6(gsignal+0x35) [0x2ab2d3b29765]
[enskog:14109] [ 2] /lib/libc.so.6 [0x2ab2d3b297d0]
[enskog:14109] [ 3] /home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so(_ZN4Foam 4sqrtERNS_5FieldIdEERKNS_5UListIdEE+0x2c) [0x2ab2d2e2b59c]
[enskog:14109] [ 4] dieselFoam(_ZN4Foam4sqrtINS_12fvPatchFieldENS_7vol MeshEEENS_3tmpINS_14GeometricF ieldIdT_T0_EEEERKS8_+0x389) [0x44fac9]
[enskog:14109] [ 5] dieselFoam [0x418ae8]
[enskog:14109] [ 6] /lib/libc.so.6(__libc_start_main+0xf4) [0x2ab2d3b15b44]
[enskog:14109] [ 7] dieselFoam(_ZN4Foam11regIOobject14readIfModifiedEv +0x1d1) [0x415a19]
[enskog:14109] *** End of error message ***
mpirun noticed that job rank 0 with PID 14108 on node enskog exited on signal 15 (Terminated).
5 additional processes aborted (not shown)

[markusrehm]

Hi Anthony,

maybe I can give some hints although I am not very sure about it. First try "unset FOAM_SIGFPE" to stop the Floating Point Exception. But I think that there is something wrong with the libraries. Have a look at the tip Bernhard gave me in this thread:
http://www.cfd-online.com/OpenFOAM_D...html#POST15988

Hope you will advance. Regards Markus.

[coastal593]

Thanks very much. I unset the SIGFPE var and indeed, it stopped the floating point problem, and I will look at the library problem soon.

Of course, now I've run into another issue altogether which may very well be related to the libraries. i have my courant set at 0.5 in the simulation but at some point now it blows up and the temperature goes crazy ... a little odd, since the residual on the enthalpy is still nice a low. i'm wondering if i should lock down my courant number to something absurd OR perhaps switch to another solver other than DILUPBiCG. of course, it could just as easily be a problem in my boundary conditions (which i listed above).

i'll be looking at this problem ... its important i get this simulation done! if anyone has any input a long the way, thanks!

anthony

Number of parcels in system | 43
Injected liquid mass....... | 1.13754e-07 mg
Liquid Mass in system...... | 1.13754e-07 mg
SMD, Dmax.................. | 2.59635 mu, 5.24868 mu
Added gas mass = 4.48518e-06 mg
Evaporation Continuity Error| 4.48518e-06 mg
ExecutionTime = 4072.86 s ClockTime = 4073 s

Courant Number mean: 2.32052e-07 max: 4.91686
deltaT = 2.77372e-10
Time = 1.12905e-07

Evolving Spray
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 7.78604e-07, Final residual = 7.78604e-07, No Iterations 0
DILUPBiCG: Solving for Uy, Initial residual = 9.68271e-07, Final residual = 9.68271e-07, No Iterations 0
DILUPBiCG: Solving for Uz, Initial residual = 0.000134054, Final residual = 3.4906e-09, No Iterations 2
DILUPBiCG: Solving for O2, Initial residual = 1.74661e-06, Final residual = 2.3743e-09, No Iterations 1
DILUPBiCG: Solving for H2O, Initial residual = 3.378e-07, Final residual = 3.378e-07, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 2.27428e-06, Final residual = 2.2472e-09, No Iterations 1
[0]
[0]
[0] --> FOAM FATAL ERROR : attempt to use janafThermo<equationofstate> out of temperature range 200 -> 5000; T = 30.8797#0 Foam::error::printStack(Foam:stream&) in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::error::abort() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 Foam::specieThermo<foam::janafthermo<foam::perfect gas> >::H(double) const in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libcombustionThermophy sicalModels.so"
#3 Foam::hMixtureThermo<foam::reactingmixture>::calcu late() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libcombustionThermophy sicalModels.so"
#4 Foam::hMixtureThermo<foam::reactingmixture>::corre ct() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libcombustionThermophy sicalModels.so"
#5 main in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
#6 __libc_start_main in "/lib/libc.so.6"
#7 Foam::regIOobject::readIfModified() in "/home/acosta/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/dieselFoa m"
[0]
[0]
[0] From function janafThermo<equationofstate>::checkT(const scalar T) const
[0] in file /home/dm2/henry/OpenFOAM/OpenFOAM-1.4.1/src/thermophysicalModels/specie/lnInclud e/janafThermoI.H at line 73.
[0]
FOAM parallel run aborting
[0]

[N. A.]

Hi Markus,

How and where should we unset SIG_FPE. In etc/bashrc.

I have used export FOAM_SIGFPE=false, but it seems this does not work.

Thanks,
Nir