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January 14, 2009, 10:42 |
Hello!
Currently I'm using
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#1 |
Member
Andreas Dietz
Join Date: Mar 2009
Location: Munich
Posts: 79
Rep Power: 17 |
Hello!
Currently I'm using OpenFOAM-1.5.x and ran in some problem with dieselFoam. In detail: For reasons of creating a new solver I use the aachenBomb tutorial as playground. Executing dieselFoam with the following controlDict *********************** application dieselFoam; startFrom latestTime; startTime 0; stopAt writeNow; endTime 0.01; deltaT 2.5e-06; writeControl timeStep; writeInterval 1; purgeWrite 0; writeFormat binary; writePrecision 6; writeCompression uncompressed; timeFormat general; timePrecision 6; adjustTimeStep yes; maxCo 0.1; runTimeModifiable yes; *********************** dieselFoam computes one time step without any problem. But when I try to continue computation from the last time step computation starts, but only reaches "Evolving spray" and nothing more happens, especially no Error Message is prompted. Anybody knows how to solve this problem? Regards, Andreas |
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January 14, 2009, 18:23 |
Is it possible that your probl
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#2 |
Senior Member
Join Date: Mar 2009
Posts: 854
Rep Power: 22 |
Is it possible that your problem relates to
stopAt writeNow; H |
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January 15, 2009, 04:21 |
Not in this case.
writeNow
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#3 |
Member
Andreas Dietz
Join Date: Mar 2009
Location: Munich
Posts: 79
Rep Power: 17 |
Not in this case.
writeNow is actually set to just compute one time step in each iteration. Although I changed the setting to stopAt endTime; and gave it a try. The result was the same. Just to get it right, computation starts, when i continue from "latestTime" but dieselFoam is only working until "Evolving Spray". From thereon nothing more happens. ****************************** dietz@typhoon:~/OpenFOAM/OpenFOAM-1.5.x/tutorials/dieselFoam/aachenBomb> dieselFoam /*---------------------------------------------------------------------------*\ | ========= | | | \ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \ / O peration | Version: 1.5.x | | \ / A nd | Web: http://www.OpenFOAM.org | | \/ M anipulation | | \*---------------------------------------------------------------------------*/ Exec : dieselFoam Date : Jan 15 2009 Time : 09:15:12 Host : typhoon PID : 22884 Case : /home/dietz/OpenFOAM/OpenFOAM-1.5.x/tutorials/dieselFoam/aachenBomb nProcs : 1 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 2.94118e-06 Reading thermophysicalProperties Selecting thermodynamics package hMixtureThermo<reactingmixture> Selecting chemistryReader chemkinReader Reading field U Reading/calculating face flux field phi Creating turbulence model. Selecting RAS turbulence model kEpsilon kEpsilonCoeffs { Cmu 0.09; C1 1.44; C2 1.92; C3 -0.33; alphah 1; alphak 1; alphaEps 0.76923; muLimiter on; Lsgs 0.0002; } Creating field DpDt Constructing chemical mechanism Selecting ODE solver SIBS chemistryModel::chemistryModel: Number of species = 5 and reactions = 1 Reading environmentalProperties Reading combustion properties Constructing Spray Selecting injectorType unitInjector Selecting atomizationModel off Selecting dragModel standardDragModel Selecting evaporationModel standardEvaporationModel Selecting heatTransferModel RanzMarshall Selecting wallModel reflect Selecting breakupModel ReitzKHRT Selecting collisionModel off Selecting dispersionModel off Selecting injectorModel hollowConeInjector Selecting pdfType RosinRammler Average Velocity for injector 0: 283.853 m/s, injection pressure = 287.387 bar Constructing three dimensional spray injection. Courant Number mean: 1.67463e-08 max: 4.00535e-05 Starting time loop Courant Number mean: 8.36195e-06 max: 0.02 deltaT = 0.000299599 Time = 0.000302541 Evolving Spray ****************************** The only thing I changed in the aachenBomb tutorial is the controlDict. Does dieselFoam restart correctly on your machine? |
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January 19, 2009, 18:16 |
> Does dieselFoam restart corr
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#4 |
Senior Member
Join Date: Mar 2009
Posts: 854
Rep Power: 22 |
> Does dieselFoam restart correctly on your machine?
Generally yes but I have repeated your setup above and can reproduce the behavior, i.e. restarting after 1 time-step causes the spray evolution to go into an infinite-loop. We are investigating.... H |
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January 20, 2009, 10:31 |
We have isolated the problem,
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#5 |
Senior Member
Join Date: Mar 2009
Posts: 854
Rep Power: 22 |
We have isolated the problem, it relates to how the time-step is adjusted on restart corresponding to the current maximum Courant number. We have pushed a fix into the 1.5.x git repository, pleas let us know if it solved your problem.
Thanks for the bug report H |
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January 20, 2009, 11:09 |
Well, thank YOU for fixing it.
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#6 |
Member
Andreas Dietz
Join Date: Mar 2009
Location: Munich
Posts: 79
Rep Power: 17 |
Well, thank YOU for fixing it.
I will update my 1.5.x asap, but in the moment it seems like I can't get a connection to the repo. I will try the following hours/days! |
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January 21, 2009, 12:43 |
Thank you, I updated my OF and
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#7 |
Member
Andreas Dietz
Join Date: Mar 2009
Location: Munich
Posts: 79
Rep Power: 17 |
Thank you, I updated my OF and simulation runs smoothly now.
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February 21, 2009, 14:50 |
Hi Pr. Henry
I am trying to
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#8 |
Senior Member
Alexandre Pereira
Join Date: Mar 2009
Posts: 155
Rep Power: 17 |
Hi Pr. Henry
I am trying to port soot formation kinetics and thermal radiation propagation to dieselFoam ... So I must first understand the models involved in spray modelling, dropplet atomization... etc. So, my start will be dieselFoam... but I have a problem... In OpenFOAM-1.3 the settings in fvSolution and fvSchemes allowed the solution of aachenBomb test case to converge... but this does not happen in dieselFoam version of OpenFOAM-1.5 Starting from the settings in the tutorial, considering the simple kinetic model of chem.inp, the solution aborts stating that the temperature is outside of the range of janafThermo... so following the advice of another post, i have changed all the settings of laplacian discretization in fvSchemes to Gauss linear limited 01, increased the number of PISO correctors to 4 in fvSolution, and changed the settings of enthalpy discretization to Gauss upwind. Still the same problem occurs... NOTE: I am using the mesh that came with the tutorial: hexahedral mesh built with blockmesh... The only thing that i have not tried yet ( I am using a windows port of OpenFOAM-1.5.x compiled under mingw32, because my linux box is away in repair shop ) was to refineMesh my case, because if I do so, not even a 4GB win Vista can swallow allt the VectorFields and scalarFields that the solution will create, aborting with a badMalloc error... Do you have any hint on what can I do to make aachenBomb of OpenFOAM-1.5.x run...? Another (un)related question : If I am to model an HCCI engine, considering that the premixed charge forms by rapid evaporation of a spray within the cylinder, I rather use the reactingFoam solver than the engineFoam (requiring a spark initiation fof the flame kernel ) or the dieselFoam ( which models a spray dynamics and a droplet evaporation process, which in an HCCI is very fast and essentially complete at the time of maximum compression) am I right here...? Thanks for your answer Best regards Alexandre |
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February 21, 2009, 14:54 |
Hi Pr. Henry
I am trying to
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#9 |
Senior Member
Alexandre Pereira
Join Date: Mar 2009
Posts: 155
Rep Power: 17 |
Hi Pr. Henry
I am trying to port soot formation kinetics and thermal radiation propagation to dieselFoam ... So I must first understand the models involved in spray modelling, dropplet atomization... etc. So, my start will be dieselFoam... but I have a problem... In OpenFOAM-1.3 the settings in fvSolution and fvSchemes allowed the solution of aachenBomb test case to converge... but this does not happen in dieselFoam version of OpenFOAM-1.5 Starting from the settings in the tutorial, considering the simple kinetic model of chem.inp, the solution aborts stating that the temperature is outside of the range of janafThermo... so following the advice of another post, i have changed all the settings of laplacian discretization in fvSchemes to Gauss linear limited 01, increased the number of PISO correctors to 4 in fvSolution, and changed the settings of enthalpy discretization to Gauss upwind. Still the same problem occurs... NOTE: I am using the mesh that came with the tutorial: hexahedral mesh built with blockmesh... The only thing that i have not tried yet ( I am using a windows port of OpenFOAM-1.5.x compiled under mingw32, because my linux box is away in repair shop ) was to refineMesh my case, because if I do so, not even a 4GB win Vista can swallow allt the VectorFields and scalarFields that the solution will create, aborting with a badMalloc error... Do you have any hint on what can I do to make aachenBomb of OpenFOAM-1.5.x run...? Another (un)related question : If I am to model an HCCI engine, considering that the premixed charge forms by rapid evaporation of a spray within the cylinder, I rather use the reactingFoam solver than the engineFoam (requiring a spark initiation fof the flame kernel ) or the dieselFoam ( which models a spray dynamics and a droplet evaporation process, which in an HCCI is very fast and essentially complete at the time of maximum compression) am I right here...? Thanks for your answer Best regards Alexandre |
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