Ratio of convective and radiative heat flux

Jiffy · July 25, 2018, 10:28

Hi everybody,

I´m solving this problem - I have heat source (100 W) in room. I need to set up the release from the heat source as a ratio of convection:radiation = 30:70. I can set up overall heat flux, and Fluent gives me radiative heat flux in post-pro. But when I count the ratio (based on results from fluent), it is about 40:60. Is it posible to set up the ratio directly as (e.g.) boundary condition?

Thanks for help, Jiffy

LuckyTran · July 25, 2018, 14:37

Not really, the point of Fluent is to solve transport equations, i.e. to figure out how the heat is transferred. If you want to impose this as a constraint, then you should not be solving transport equations in the first place.

You have to think about why you think the correct heat flux should be 30:70 because Fluent thinks it should be 40:60. Maybe some other boundary condition needs to give.

July 25, 2018, 10:28	Ratio of convective and radiative heat flux	#1
Jiffy New Member Jiffy Join Date: May 2016 Posts: 5 Rep Power: 10	Hi everybody, I´m solving this problem - I have heat source (100 W) in room. I need to set up the release from the heat source as a ratio of convection:radiation = 30:70. I can set up overall heat flux, and Fluent gives me radiative heat flux in post-pro. But when I count the ratio (based on results from fluent), it is about 40:60. Is it posible to set up the ratio directly as (e.g.) boundary condition? Thanks for help, Jiffy

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July 25, 2018, 14:37		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	Not really, the point of Fluent is to solve transport equations, i.e. to figure out how the heat is transferred. If you want to impose this as a constraint, then you should not be solving transport equations in the first place. You have to think about why you think the correct heat flux should be 30:70 because Fluent thinks it should be 40:60. Maybe some other boundary condition needs to give.