Buoyancy flow

sunilpatil · December 17, 2014, 13:39

Hello Sir,
I am modelling buoyancy induced transient flow in an Air cavity and for that i am using Bossiness approximation. For steady state flows, we use to consider Average domain temperature as a buoyancy reference temperature which is constant. My question is, is it we need to considered constant buoyancy reference temperature for transient flow and what should be the buoyancy reference location.

Thank you
Suneel

ghorrocks · December 17, 2014, 19:30

For transient simulations use a reference temperature which is in the middle of the range of temperatures you expect to see over the course of the simulation, and a reference point in a region where the flow is simple.

The precise choice of reference temperature and point should not be important. You should be able to change it by quite a bit and it makes no difference to the simulation result.

December 17, 2014, 13:39	Buoyancy flow	#1
sunilpatil Senior Member sunil Join Date: Jul 2012 Location: Bangalore Posts: 179 Rep Power: 14	Hello Sir, I am modelling buoyancy induced transient flow in an Air cavity and for that i am using Bossiness approximation. For steady state flows, we use to consider Average domain temperature as a buoyancy reference temperature which is constant. My question is, is it we need to considered constant buoyancy reference temperature for transient flow and what should be the buoyancy reference location. Thank you Suneel

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December 17, 2014, 19:30		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	For transient simulations use a reference temperature which is in the middle of the range of temperatures you expect to see over the course of the simulation, and a reference point in a region where the flow is simple. The precise choice of reference temperature and point should not be important. You should be able to change it by quite a bit and it makes no difference to the simulation result.