chtMultiRegionSimpleFoam Problem with liquids since 2.0

albertinho · July 29, 2011, 06:58

Hello,

in OpenFOAM-2.0.x is a Problem in the chtMultiRegionSimpleFoam-solver with the handling of liquids.

The Problem is in the fluid/hEqun.H, because since 1.7 the pressure p is replaced by rho/psi, and this leads to a SIGFPE because psi is 0 for a liquid.

Can anyone explain me this change?

Regards
Wolfgang

alberto · July 30, 2011, 03:06

You might want to report the problem on OpenCFD bug tracker: http://www.openfoam.com/mantisbt/main_page.php

albertinho · August 2, 2011, 09:58

Hello Alberto,

thanks for the hint, I've reported it and it is already changed.

But I already have a new problem. I want to make a transient Simulation of a water-glycol-cooler with the chtMultiRegion-solver. The initial state is a solution of the chtMultiRegionSimpleFoam. But it doesn't work, after about 2 time steps the solution diverges with very high temperatures. I tried to change the solution controls or the interpolation schemes, but nothing helps.

Then I looked into the code, again in the enthalpy equation, but this time of the chtMultiRegion-solver. I found the term DpDt wich is calculated in the pEqun.H - file.

Isn't it a term, which should only for compressible fluids in the enthalpy equation?

I commented the DpDt out in my own own version and it works.

Is this also a bug ?

Regards
Wolfgang

July 29, 2011, 06:58	chtMultiRegionSimpleFoam Problem with liquids since 2.0	#1
albertinho New Member Wolfgang Schnell Join Date: Aug 2009 Location: Munich Posts: 4 Rep Power: 16	Hello, in OpenFOAM-2.0.x is a Problem in the chtMultiRegionSimpleFoam-solver with the handling of liquids. The Problem is in the fluid/hEqun.H, because since 1.7 the pressure p is replaced by rho/psi, and this leads to a SIGFPE because psi is 0 for a liquid. Can anyone explain me this change? Regards Wolfgang

July 30, 2011, 03:06		#2
alberto Senior Member Alberto Passalacqua Join Date: Mar 2009 Location: Ames, Iowa, United States Posts: 1,912 Rep Power: 36	You might want to report the problem on OpenCFD bug tracker: http://www.openfoam.com/mantisbt/main_page.php __________________ Alberto Passalacqua GeekoCFD - A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats (current status: http://albertopassalacqua.com/?p=1541) OpenQBMM - An open-source implementation of quadrature-based moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using.

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August 2, 2011, 09:58		#3
albertinho New Member Wolfgang Schnell Join Date: Aug 2009 Location: Munich Posts: 4 Rep Power: 16	Hello Alberto, thanks for the hint, I've reported it and it is already changed. But I already have a new problem. I want to make a transient Simulation of a water-glycol-cooler with the chtMultiRegion-solver. The initial state is a solution of the chtMultiRegionSimpleFoam. But it doesn't work, after about 2 time steps the solution diverges with very high temperatures. I tried to change the solution controls or the interpolation schemes, but nothing helps. Then I looked into the code, again in the enthalpy equation, but this time of the chtMultiRegion-solver. I found the term DpDt wich is calculated in the pEqun.H - file. Isn't it a term, which should only for compressible fluids in the enthalpy equation? I commented the DpDt out in my own own version and it works. Is this also a bug ? Regards Wolfgang