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solver for supersonic flow butane close to condensation |
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April 10, 2017, 07:00 |
solver for supersonic flow butane close to condensation
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#1 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
Dear all,
I'm looking for a solver to simulate a flow through a nozzle in supersonic condition (about Mach 2) but with the possibility to evaluate the condensation of butane gas, due to conditions very close to the condensation of this gas. As a starting point I'm considering sonicFoam solver, but I don't think it cover also the condensation possibility. What do you suggest? Moreover, how to implement the use of the Redlich-Kwong equation to consider the gas according to a real behaviour about calculating p, rho and T? I read how to set a thermophysical model but it is not clear how to set a good one model for the butane. Is there a database where is possible to get a proper model for butane gas? Moreover, I found some libraries, like this one but I don't know how to use them. Could anyone help on the way? I'm just evaluating all possibilities I can have in OpenFOAM. Thanks to who wants to help me! Last edited by enginpower; April 11, 2017 at 11:24. Reason: updating |
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April 18, 2017, 10:05 |
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#2 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
No one can add some useful helps to this thread??!
I'm reading a lot of useful tutorials on the web but sometimes it's hard to understand how it will work in my case. I'm focusing on the solver sonicFoam, but I've not understood how to perform a steady-state simulation. Practically, I'm not interested in the evolution of time, but I've not understood how to do that since sonicFoam is for unsteady simulation. |
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April 24, 2017, 12:51 |
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#3 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
I tried to solve this case also with rhoSimpleFoam.
The problem is that it diverges but it is not clear why. With this script: Code:
#!/bin/bash foamLog log >/dev/null gnuplot -persist > /dev/null 2>&1 << EOF set logscale y set title "Residual vs. Iteration" set xlabel "Iteration" set ylabel "Residual" plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,\ "< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,\ "< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,\ "< cat log | grep 'Solving for U' | cut -d' ' -f9 | tr -d ','" title 'U' with lines,\ "< cat log | grep 'Solving for e' | cut -d' ' -f9 | tr -d ','" title 'e' with lines,\ "< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines,\ "< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,\ "< cat log | grep 'Solving for epsilon' | cut -d' ' -f9 | tr -d ','" title 'epsilon' with lines,\ "< cat log | grep 'Solving for T' | cut -d' ' -f9 | tr -d ','" title 'T' with lines,\ "< cat log | grep 'Solving for nut' | cut -d' ' -f9 | tr -d ','" title 'nut' with lines,\ "< cat log | grep 'Solving for alphat' | cut -d' ' -f9 | tr -d ','" title 'alphat' with lines EOF What I obtained is this: rhoSimpleFoam.jpg Not clear why does it not plot U, Ux, Uy and Uz, and the other variables, and moreover why 'e' has more iterations than other variables? It will worthly help me to find the solution to my specific simulation |
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May 4, 2017, 08:40 |
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#4 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
Could someone provide some useful helps to find a solution?
Mainly I don't understand why it doesn't plot all the variables and why some variables have more iterations than others. I'll try some helpful suggestions, but now I'm stuck on this. Thanks!! |
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May 4, 2017, 09:35 |
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#5 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
This is the log file solver outputed, if it can help:
Code:
/*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 4.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : 4.1 Exec : rhoSimpleFoam Date : May 04 2017 Time : 14:19:39 Host : "engine-VirtualBox" PID : 4696 Case : /home/engine/OpenFoam/diffuse_rhoSimpleFoam nProcs : 1 sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). fileModificationChecking : Monitoring run-time modified files using timeStampMaster allowSystemOperations : Allowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 0 SIMPLE: convergence criteria field p tolerance 0.01 field U tolerance 0.0001 field e tolerance 0.001 field "(k|epsilon|omega)" tolerance 0.001 Reading thermophysical properties Selecting thermodynamics package { type hePsiThermo; mixture pureMixture; transport sutherland; thermo janaf; equationOfState PengRobinsonGas; specie specie; energy sensibleInternalEnergy; } Reading field U Reading/calculating face flux field phi Creating turbulence model Selecting turbulence model type RAS Selecting RAS turbulence model kEpsilon kEpsilonCoeffs { Cmu 0.09; C1 1.44; C2 1.92; C3 -0.33; sigmak 1; sigmaEps 1.3; } No MRF models present No finite volume options present Starting time loop Time = 1 smoothSolver: Solving for e, Initial residual = 1, Final residual = 0.0540073, No Iterations 1 GAMG: Solving for p, Initial residual = 1, Final residual = 0.00371374, No Iterations 1 time step continuity errors : sum local = 0.146365, global = 0.074303, cumulative = 0.074303 rho max/min : 4.84782 2.38329 smoothSolver: Solving for epsilon, Initial residual = 0.172435, Final residual = 0.00961314, No Iterations 2 smoothSolver: Solving for k, Initial residual = 1, Final residual = 0.0693484, No Iterations 2 ExecutionTime = 39.26 s ClockTime = 39 s Time = 2 smoothSolver: Solving for e, Initial residual = 0.206248, Final residual = 0.0125807, No Iterations 1 GAMG: Solving for p, Initial residual = 0.497519, Final residual = 0.00163633, No Iterations 1 time step continuity errors : sum local = 0.0922393, global = 0.00722332, cumulative = 0.0815263 rho max/min : 4.68042 2.30108 smoothSolver: Solving for epsilon, Initial residual = 0.081466, Final residual = 0.00135644, No Iterations 4 smoothSolver: Solving for k, Initial residual = 0.135448, Final residual = 0.00222524, No Iterations 4 ExecutionTime = 60.8 s ClockTime = 61 s Time = 3 smoothSolver: Solving for e, Initial residual = 0.0921914, Final residual = 0.0067252, No Iterations 1 GAMG: Solving for p, Initial residual = 0.295628, Final residual = 0.00206877, No Iterations 1 time step continuity errors : sum local = 0.1348, global = -0.0479959, cumulative = 0.0335304 rho max/min : 4.5214 2.22033 smoothSolver: Solving for epsilon, Initial residual = 0.0482015, Final residual = 0.00140061, No Iterations 4 smoothSolver: Solving for k, Initial residual = 0.0592527, Final residual = 0.00145718, No Iterations 4 ExecutionTime = 81.9 s ClockTime = 82 s Time = 4 smoothSolver: Solving for e, Initial residual = 0.0537717, Final residual = 0.0046956, No Iterations 1 GAMG: Solving for p, Initial residual = 0.184845, Final residual = 0.00221746, No Iterations 1 time step continuity errors : sum local = 0.157532, global = -0.0805149, cumulative = -0.0469844 rho max/min : 4.37033 2.14308 smoothSolver: Solving for epsilon, Initial residual = 0.0371772, Final residual = 0.00132592, No Iterations 4 smoothSolver: Solving for k, Initial residual = 0.0359271, Final residual = 0.0011415, No Iterations 4 ExecutionTime = 102.71 s ClockTime = 102 s Time = 5 smoothSolver: Solving for e, Initial residual = 0.037143, Final residual = 0.00366518, No Iterations 1 GAMG: Solving for p, Initial residual = 0.119611, Final residual = 0.00216066, No Iterations 1 time step continuity errors : sum local = 0.162309, global = -0.094971, cumulative = -0.141955 rho max/min : 4.22682 2.06984 smoothSolver: Solving for epsilon, Initial residual = 0.0308441, Final residual = 0.00137104, No Iterations 4 smoothSolver: Solving for k, Initial residual = 0.0255359, Final residual = 0.000959661, No Iterations 4 ExecutionTime = 123.21 s ClockTime = 123 s Time = 6 smoothSolver: Solving for e, Initial residual = 0.0281171, Final residual = 0.000449398, No Iterations 2 GAMG: Solving for p, Initial residual = 0.0798722, Final residual = 0.00201198, No Iterations 1 time step continuity errors : sum local = 0.155986, global = -0.0975481, cumulative = -0.239504 rho max/min : 4.09048 2.00056 smoothSolver: Solving for epsilon, Initial residual = 0.0354407, Final residual = 0.00139249, No Iterations 4 bounding epsilon, min: -3030.03 max: 17421.2 average: 207.091 smoothSolver: Solving for k, Initial residual = 0.0198908, Final residual = 0.000838357, No Iterations 4 ExecutionTime = 143.7 s ClockTime = 143 s Time = 7 smoothSolver: Solving for e, Initial residual = 0.0222361, Final residual = 0.000380718, No Iterations 2 GAMG: Solving for p, Initial residual = 0.054566, Final residual = 0.00182607, No Iterations 1 time step continuity errors : sum local = 0.144461, global = -0.093211, cumulative = -0.332715 rho max/min : 3.96095 1.93506 smoothSolver: Solving for epsilon, Initial residual = 0.0336136, Final residual = 0.00138304, No Iterations 4 bounding epsilon, min: -398.097 max: 18157.5 average: 207.952 smoothSolver: Solving for k, Initial residual = 0.0164301, Final residual = 0.000750733, No Iterations 4 ExecutionTime = 163.52 s ClockTime = 163 s Time = 8 smoothSolver: Solving for e, Initial residual = 0.0183909, Final residual = 0.000333399, No Iterations 2 GAMG: Solving for p, Initial residual = 0.0381647, Final residual = 0.00164253, No Iterations 1 time step continuity errors : sum local = 0.131653, global = -0.0852954, cumulative = -0.41801 rho max/min : 3.8379 1.87311 smoothSolver: Solving for epsilon, Initial residual = 0.0452828, Final residual = 0.00157203, No Iterations 4 bounding epsilon, min: -5692.65 max: 18873.5 average: 208.924 smoothSolver: Solving for k, Initial residual = 0.0140894, Final residual = 0.00068383, No Iterations 4 ExecutionTime = 183.43 s ClockTime = 183 s Time = 9 smoothSolver: Solving for e, Initial residual = 0.0156991, Final residual = 0.00029791, No Iterations 2 GAMG: Solving for p, Initial residual = 0.0276336, Final residual = 0.000595807, No Iterations 2 time step continuity errors : sum local = 0.0477531, global = -0.0296898, cumulative = -0.4477 rho max/min : 3.72101 1.81453 smoothSolver: Solving for epsilon, Initial residual = 0.0441157, Final residual = 0.00148421, No Iterations 4 bounding epsilon, min: -745.382 max: 19567.6 average: 209.922 smoothSolver: Solving for k, Initial residual = 0.0125306, Final residual = 0.000631366, No Iterations 4 ExecutionTime = 202.69 s ClockTime = 202 s Time = 10 smoothSolver: Solving for e, Initial residual = 0.0136794, Final residual = 0.000269679, No Iterations 2 GAMG: Solving for p, Initial residual = 0.020065, Final residual = 0.000521133, No Iterations 2 time step continuity errors : sum local = 0.0423525, global = -0.0250551, cumulative = -0.472755 rho max/min : 3.60996 1.75873 smoothSolver: Solving for epsilon, Initial residual = 0.0661285, Final residual = 0.00193734, No Iterations 4 bounding epsilon, min: -12255.9 max: 20241.8 average: 211.066 smoothSolver: Solving for k, Initial residual = 0.0117622, Final residual = 0.000553884, No Iterations 4 ExecutionTime = 221.44 s ClockTime = 221 s Time = 11 smoothSolver: Solving for e, Initial residual = 0.0121028, Final residual = 0.000246455, No Iterations 2 GAMG: Solving for p, Initial residual = 0.0152189, Final residual = 0.000464024, No Iterations 2 time step continuity errors : sum local = 0.037845, global = -0.0211324, cumulative = -0.493887 rho max/min : 3.50446 1.70564 smoothSolver: Solving for epsilon, Initial residual = 0.0631682, Final residual = 0.00171955, No Iterations 4 bounding epsilon, min: -1319.43 max: 21681.1 average: 212.209 smoothSolver: Solving for k, Initial residual = 0.0100108, Final residual = 0.000557271, No Iterations 4 ExecutionTime = 240.19 s ClockTime = 240 s Time = 12 Last edited by enginpower; May 9, 2017 at 09:38. |
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May 4, 2017, 11:51 |
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#6 |
Member
power
Join Date: Jun 2014
Posts: 86
Rep Power: 12 |
Another question is:
why should it stop if all variable residual variables are below 0.1? Is there another problem about its stop? How to check it? I have just this: Code:
rhoSimpleFoam > log #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libc.so.6" #3 ? in "/lib/x86_64-linux-gnu/libm.so.6" #4 pow in "/lib/x86_64-linux-gnu/libm.so.6" #5 Foam::PengRobinsonGas<Foam::specie>::Z(double, double) const at ??:? #6 Foam::PengRobinsonGas<Foam::specie>::cp(double, double) const at ??:? #7 Foam::janafThermo<Foam::PengRobinsonGas<Foam::specie> >::cp(double, double) const at ??:? #8 Foam::heThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::janafThermo<Foam::PengRobinsonGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::CpByCpv() const at ??:? #9 Foam::heThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::janafThermo<Foam::PengRobinsonGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::alphaEff(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) const at ??:? #10 Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::CompressibleTurbulenceModel<Foam::fluidThermo> > >::alphaEff() const at ??:? #11 ? at ??:? #12 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #13 ? at ??:? Floating point exception (core dumped) |
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Tags |
butane, condensation model, supersonic flow |
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