Steam exhaust to air

semo · October 25, 2012, 16:18

Hello,

I am trying to simulate hot steam (1000F,4000psi) exhausting to the ambient air. I am using steam-air mixture with species transport model. Steam comes out from a nozzle to a larger pipe and then exhausts to the ambient air. Initially pipe is filled with ambient air.

I am using ideal gas approach for the steam and air density. I am trying to solve 2d transient but I am having difficulty with the convergence. When I use pressure based solver I can get couple of time steps converged but then it keeps decreasing the time steps and at some point it stops with floating point exception. Even with the converged time steps velocity fields doesnt make sense. I see very high velocities in the ambient air very far from the exhaust. I had less luck with the density based solver.

Does anybody have experience solving this kind of a problem? Any help will be appreciated. Thanks in advance.

semo

semo · November 5, 2012, 17:16

Does anybody have any idea regarding this? Please help if you do, thanks...

October 25, 2012, 16:18	Steam exhaust to air	#1
semo Member Join Date: Jun 2010 Posts: 31 Rep Power: 16	Hello, I am trying to simulate hot steam (1000F,4000psi) exhausting to the ambient air. I am using steam-air mixture with species transport model. Steam comes out from a nozzle to a larger pipe and then exhausts to the ambient air. Initially pipe is filled with ambient air. I am using ideal gas approach for the steam and air density. I am trying to solve 2d transient but I am having difficulty with the convergence. When I use pressure based solver I can get couple of time steps converged but then it keeps decreasing the time steps and at some point it stops with floating point exception. Even with the converged time steps velocity fields doesnt make sense. I see very high velocities in the ambient air very far from the exhaust. I had less luck with the density based solver. Does anybody have experience solving this kind of a problem? Any help will be appreciated. Thanks in advance. semo

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November 5, 2012, 17:16		#2
semo Member Join Date: Jun 2010 Posts: 31 Rep Power: 16	Does anybody have any idea regarding this? Please help if you do, thanks...