Is it possible to integrate air through a system with mixture of air and water?

Hale · September 30, 2013, 07:35

Hi to all,

I'm using interFoam solver for solving flow through a vertical pipe with mixture of air and water. I want to check the mass conservation of air through the system by comparing the air at the inlet and outlet. In order to do that I have to find the quantities in the following equation:

Qair_inlet = Qair_domain + Qair_outlet

I can easily find the inlet and outlet air fluxes but I don't know how to find the air in the domain. Is there any way to integrate the air bobbles in the domain in OpenFOAM?

Thanks

haakon · September 30, 2013, 09:57

You can integrate up either alpha1*U&Sf() or (1-alpha1)*U&Sf() at the inlet and outlet boundaries, depending on whether alpha1 is the phase fraction of water or air.

One other alternative is possibly to integrate alpha1 over the entire domain volume, that will give you the volume of that phase (air or water) present at each timestep.

You can get some hints here: https://www.hpc.ntnu.no/display/hpc/...Postprocessing (check the latest part about volume flow out of the domain).

September 30, 2013, 07:35	Is it possible to integrate air through a system with mixture of air and water?	#1
Hale Member Hale Join Date: May 2013 Posts: 53 Rep Power: 13	Hi to all, I'm using interFoam solver for solving flow through a vertical pipe with mixture of air and water. I want to check the mass conservation of air through the system by comparing the air at the inlet and outlet. In order to do that I have to find the quantities in the following equation: Qair_inlet = Qair_domain + Qair_outlet I can easily find the inlet and outlet air fluxes but I don't know how to find the air in the domain. Is there any way to integrate the air bobbles in the domain in OpenFOAM? Thanks

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September 30, 2013, 09:57		#2
haakon Senior Member Join Date: Dec 2011 Posts: 111 Rep Power: 20	You can integrate up either alpha1U&Sf() or (1-alpha1)U&Sf() at the inlet and outlet boundaries, depending on whether alpha1 is the phase fraction of water or air. One other alternative is possibly to integrate alpha1 over the entire domain volume, that will give you the volume of that phase (air or water) present at each timestep. You can get some hints here: https://www.hpc.ntnu.no/display/hpc/...Postprocessing (check the latest part about volume flow out of the domain).