Modeling the power sources

saisanthoshm88 · April 6, 2011, 13:21

I’m currently working on a electronics cooling problem with some embeded system component.

I had a question in modeling the Power sources in the system.

The information available is that these power sources are typical battery units generating a power of 12 KW .

When these are meshed in the fluid domain the case is that the bounding surfaces of these power sources wont be meshed fully due to the existence of other adjacent surfaces that interrupt the fluid ( Air) flow there.
This is quite obvious and isn’t a problem at all.

But my question is that though these surfaces bounding the power sources get only partly meshed while in the fluid domain, is it fine to define this energy of 12 KW in terms of a surface heat flux (or) do I need to model these power sources as solid domains and then add them as volumetric heat sources to the simulation.
Please suggest upon the right approach

ghorrocks · April 6, 2011, 19:44

A volumetric heat flux to the body will give a heat flux distribution over the body. If you apply 12kW heat flux over the surfaces it will be evenly distributed (unless you set a function to vary it).

So whether an even heat flux is a good representation of what you are trying to do will depend on the details of your model, so you will have to determine that.

ghorrocks · April 6, 2011, 19:46

An easy approach is just to model both approaches (even surface flux and volumetric flux) and compare the difference. If the difference is negligible than use the simpler constant heat flux. If it is an important difference you have to use volumetric heat flux.

And is the volumetric heat flux even? It is probably biased towards something anyway.

April 6, 2011, 13:21	Modeling the power sources	#1
saisanthoshm88 Senior Member --------- Join Date: Oct 2010 Posts: 303 Rep Power: 18	I’m currently working on a electronics cooling problem with some embeded system component. I had a question in modeling the Power sources in the system. The information available is that these power sources are typical battery units generating a power of 12 KW . When these are meshed in the fluid domain the case is that the bounding surfaces of these power sources wont be meshed fully due to the existence of other adjacent surfaces that interrupt the fluid ( Air) flow there. This is quite obvious and isn’t a problem at all. But my question is that though these surfaces bounding the power sources get only partly meshed while in the fluid domain, is it fine to define this energy of 12 KW in terms of a surface heat flux (or) do I need to model these power sources as solid domains and then add them as volumetric heat sources to the simulation. Please suggest upon the right approach __________________ Best regards, Santhosh.

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April 6, 2011, 19:44		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	A volumetric heat flux to the body will give a heat flux distribution over the body. If you apply 12kW heat flux over the surfaces it will be evenly distributed (unless you set a function to vary it). So whether an even heat flux is a good representation of what you are trying to do will depend on the details of your model, so you will have to determine that.

April 6, 2011, 19:46		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	An easy approach is just to model both approaches (even surface flux and volumetric flux) and compare the difference. If the difference is negligible than use the simpler constant heat flux. If it is an important difference you have to use volumetric heat flux. And is the volumetric heat flux even? It is probably biased towards something anyway.