OpenFoam 2.2 fvOptions temperature limits
Dear all,
As some of you know, OF 2.2 introduce a new system of "fvOptions" files where we can set the porosity and so on... There is another interesting command that is "temperatureLimitsConstraint". As its name says, it is used to constraint the temperature to a minimum and maximum value. Because I didn't find any example online, here is my file: You have to put it into the "fvOptions" file located in system Code:
source1 Edit: the page description come from here: http://www.openfoam.org/version2.2.0/fvOptions.php |
Thanks for the tip!
Does this work for all compressible solvers? I tried adding this to sonicFoam and it seems to get ignored. |
As I remember, sonic foam is mostly hard coded so it might not work.
To check, find the thermo equation in the source code and check if you can find a line with "+ fvoptions" or something similar. |
Hi Fredo,
Thanks for your tip. May i know whether there exists similar options to control turbulent kinetic energy k and epsilon? ksv |
For k, omega et epsilon, you can add a simple code such as:
Code:
k= max(k, kMin); We must use fOption for T because T is not a variable used by OpenFoam. The function "fOption" actually modify the thermo equation (enthalpy) to correct the temperature. |
Hi all,
sorry for re-opening this thread but I'm using the temperatureLimitsConstraint in conjunction with chtMultiRegionFoam (OF-2.2.x, latest available update) and it actually doesn't seem to me it's working as it is supposed to. The fvOptions dict appears to be read properly, but when the enthalpy equation is solved the temperature violates the imposed bounds, even if all the discretization schemes should be bounded/limited. Here there are my fvSchemes and fvOptions dictionaries (there is only one fluid region at this stage), together with an extract of runtime output log. fvSchemes: Code:
ddtSchemes Code:
temperature_constraints Code:
Region: fluid Courant Number mean: 1.4132369e-05 max: 0.98128545 V. |
Typically in a CHT analysis, the system directory will have subdirectories for each region. Did you put the fvOptions file in the relevant subdirectory? Also, at the top of the log file, OpenFOAM will tell you what it has read from the fvOptions file.
*UPDATE* Same behavior here. Doesn't seem to limit the temperature at all. |
Quote:
Quote:
Best V. |
I was using the 2.3.x branch. Temperature in the solid blows up, not obeying the fvOptions limit. I suspect that, for some reason, diffusion at the boundary becomes zero thus zero heat flux at the boundary and the applied heat flux (fixed gradient on the solid) yields a near infinite temperature on the solid. Just a guess.
|
THis does work in chtMultiRegionSimpleFoam in V2.3.1
in conjunction with scalarSemiImplicitSource to construct a heat source limited by temperature the comment in header file gives the wrong names for the coeffs it is Tmin and Tmax not maximum and minimum. Code:
Temperaturelimit1 |
Adding a fvOptions file in system folder with :
Code:
temperatureLimit |
Hi everyone
My simulation in OF v1806 using rhoSimpleFoam crashed after very few iterations due to divergence in temperature. After limiting the temperature the solver runs very well. Now the same simulation has a very similar behaviour in foam-extend 4.0 when using dbnsTurbFoam. When I tried to apply limits I realised that fvOptions is not available in the foam-extend version. Does anyone know a work around or how I can apply limits? Many thanks. |
Limit temperature within the inner loop?
Is there a way to limit temperature within the inner loop?
My temparature blows up within a loop? I am also interested in limiting the temperature for another variable interface temperature Tf? Anybody having any ideas? I am using interfacecomposition model in reactingTwoPhaseEulerFoam? Thanks Stanley |
All times are GMT -4. The time now is 11:33. |