Boundary condition for exhaut flow with imposed mass flow

stephane · April 25, 2011, 14:13

Hi,

I'm modeling the ventilation of a room with Fluent. At the inlet, I would like to use a velocity inlet BC. I have several outlets. I would like to impose the mass flow at these outlets. For instance, let's say I have an inlet with a mass flow equal to 1 kg/s and 2 outlets where the mass flow are equal to respectively 0.8 kg/s and 0.2 kg/s. Which BC should I use at the outlets? Can I use some velocity inlet BC at the outlets to impose the flowrate? Or should I use some pressure outlet boundaries with the target mass flow rate option? I could also use an outflow BC and adjust the flow rate weighting. What is the best approach.
Thanks in advance,
Stéphane

delaneyluke · November 24, 2011, 03:04

I assume your flow might be compressible. If so, the outflow condition will not be applicable. The pressure outlet BC with target mass flow is a better option.

Oops, this is a late reply. Hope it helps.

Regards
Luke

April 25, 2011, 14:13	Boundary condition for exhaut flow with imposed mass flow	#1
stephane New Member Join Date: Apr 2011 Posts: 3 Rep Power: 15	Hi, I'm modeling the ventilation of a room with Fluent. At the inlet, I would like to use a velocity inlet BC. I have several outlets. I would like to impose the mass flow at these outlets. For instance, let's say I have an inlet with a mass flow equal to 1 kg/s and 2 outlets where the mass flow are equal to respectively 0.8 kg/s and 0.2 kg/s. Which BC should I use at the outlets? Can I use some velocity inlet BC at the outlets to impose the flowrate? Or should I use some pressure outlet boundaries with the target mass flow rate option? I could also use an outflow BC and adjust the flow rate weighting. What is the best approach. Thanks in advance, Stéphane

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November 24, 2011, 03:04		#2
delaneyluke Senior Member Join Date: Mar 2009 Location: Indiana, US Posts: 186 Rep Power: 17	I assume your flow might be compressible. If so, the outflow condition will not be applicable. The pressure outlet BC with target mass flow is a better option. Oops, this is a late reply. Hope it helps. Regards Luke