PisoFoam and Gravitation

krene · October 23, 2011, 09:59

Hi

I'm new in OpenFOAM and so I do not have so much experience with changing code etc.

I do have a problem with PisoFoam. I'd like to use the buoyantPressure at the walls but I get the following error message:

Code:

request for uniformDimensionedVectorField g from objectRegistry region0 failed
    available objects of type uniformDimensionedVectorField are

0
(
)


    From function objectRegistry::lookupObject<Type>(const word&) const
    in file /home/opencfd/OpenFOAM/OpenFOAM-2.0.1/src/OpenFOAM/lnInclude/objectRegistryTemplates.C at line 131.

FOAM aborting

When I change the BC to zeroGradient, the code is running without any problems.
I think, there is a problem with the gravitation. I do have a file in constant/g which stands for the gravitation.

I saw the thread but I do not really know what to change: http://www.cfd-online.com/Forums/ope...behaviour.html

Thank you in advance for your help. Have a nice day.

The problem is running on OpenFOAM 2.0.1

alberto · October 24, 2011, 02:28

Hi,

pisoFoam does not account for the gravity, so no gravitational vector is defined when you run it. The buoyantPressure condition is equivalent to zeroGradient, if g = 0.

You might want to take a look at solvers involving buoyancy (heatTransfer directory).

Best,

krene · October 25, 2011, 02:00

Hi Alberto,

thanks for this information. I'll try with another solver.

Regards

October 23, 2011, 09:59	PisoFoam and Gravitation	#1
krene New Member rene Join Date: Oct 2011 Posts: 7 Rep Power: 14	Hi I'm new in OpenFOAM and so I do not have so much experience with changing code etc. I do have a problem with PisoFoam. I'd like to use the buoyantPressure at the walls but I get the following error message: Code: request for uniformDimensionedVectorField g from objectRegistry region0 failed available objects of type uniformDimensionedVectorField are 0 ( ) From function objectRegistry::lookupObject<Type>(const word&) const in file /home/opencfd/OpenFOAM/OpenFOAM-2.0.1/src/OpenFOAM/lnInclude/objectRegistryTemplates.C at line 131. FOAM aborting When I change the BC to zeroGradient, the code is running without any problems. I think, there is a problem with the gravitation. I do have a file in constant/g which stands for the gravitation. I saw the thread but I do not really know what to change: http://www.cfd-online.com/Forums/ope...behaviour.html Thank you in advance for your help. Have a nice day. The problem is running on OpenFOAM 2.0.1

October 24, 2011, 02:28		#2
alberto Senior Member Alberto Passalacqua Join Date: Mar 2009 Location: Ames, Iowa, United States Posts: 1,912 Rep Power: 36	Hi, pisoFoam does not account for the gravity, so no gravitational vector is defined when you run it. The buoyantPressure condition is equivalent to zeroGradient, if g = 0. You might want to take a look at solvers involving buoyancy (heatTransfer directory). Best, __________________ 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.

October 25, 2011, 02:00		#3
krene New Member rene Join Date: Oct 2011 Posts: 7 Rep Power: 14	Hi Alberto, thanks for this information. I'll try with another solver. Regards