Simulating thermal driven ventilation with humid air

ka1 · July 11, 2018, 08:08

Hello,

I am trying to simulate a thermal buoyancy driven Ventilation of a simple room through a tilted window. I was successful with using air as an ideal gas but now I want to use humid air. Do I have to use the species model in fluent? The Problem I encounterd was, that density for water vapour is const.. But it schould not be const. because the difference is the only force which drives the flow in and out of the room.
Or is there a possibility to use CFX? Because I am using opening boundarys to simulate the windstill outside area.

Thank you

`e` · July 12, 2018, 02:21

If you have a function or table of values for the fluid properties, dependent on say temperature or humidity, then you could use a user-defined function to define these properties with the DEFINE_PROPERTY macro.

July 11, 2018, 08:08	Simulating thermal driven ventilation with humid air	#1
ka1 New Member Join Date: Jul 2018 Posts: 2 Rep Power: 0	Hello, I am trying to simulate a thermal buoyancy driven Ventilation of a simple room through a tilted window. I was successful with using air as an ideal gas but now I want to use humid air. Do I have to use the species model in fluent? The Problem I encounterd was, that density for water vapour is const.. But it schould not be const. because the difference is the only force which drives the flow in and out of the room. Or is there a possibility to use CFX? Because I am using opening boundarys to simulate the windstill outside area. Thank you

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July 12, 2018, 02:21		#2
`e` Senior Member Join Date: Mar 2015 Posts: 892 Rep Power: 18	If you have a function or table of values for the fluid properties, dependent on say temperature or humidity, then you could use a user-defined function to define these properties with the DEFINE_PROPERTY macro.