# Heat plate boundry condition problem

Hello Everyone,

I think i might need some help…
I am currently trying to simulate the temperature distribution in a battery modul.
I assigned the volume cell dummies as a heat source and set the thermal resistance of the thermal interface material, a gap pad, as a contact resistance.

now i dont want to simulate the fluid flow within the cooling channels so i used basic fluid mechanics to calculate the heat conductance. my thought was, that i use a wall boundry condition, assign the conductance and give the average fluid temparature on the boundry.

But how do i specifiy the wall boundry condition correctly?
And do you have a better idea to solve this problem?

My current results ranged from -4000 K to + 4000 K

Project

Not simulating fluid defeats the purpose of using conjugate heat transfer (because conjugate heat transfer, in theory, involves both fluid and solids exchanging heat with each other).

This approach you’re taking doesn’t look very realistic IMO. Is there any specific reason for not simulating fluid flow?

And one more thing that I noticed, when you were setting the absolute power sources, did you intend to set 150 W for all 70 bodies combined or for each one? The value that you input there is applied to each one of the bodies (150*70 W).

honestly i decided to ignore fluid flow because the simulations seemed to go on for ever and i thought i might be able to reduce the problem. At this point i just wanted to know if my simulation goes in the right direction.

Also i was not sure which solver to use. The Reynolds Number is somewhere between 2300 and 5000 so no defined flow.

and thanks i wanted to set 150 for all the cells in total so this is going to make a big difference.

And for CHT after i left out fluid flow i was wondering if a heat transfer simulation might be more suitable.

(sorry about the unprofessional test descriptions… got a littlebit late yesterday)

Oh and also:

the basic idea is a proof of concept, that this type of cold plate might be suitable for 3C discharge. The Simulation should provide a basic idea of temperature uniformity (or lack thereoff). Its part of my master thesis.

It sounds like a nice project

Conjugate heat transfer simulations do take a while to run, but trying to simplify the problem too much might not be a very good idea. Personally (especially since it’s a project for a master’s thesis) I’d try to model it as accurately as I can.
For instance, you’re thinking of removing heat from the battery using these cooling channels. But heat is also removed in other ways (convection with the air around the body, radiation…).
Radiation in CHT was being tested in the past couple of weeks and should be available to all users soon if it isn’t already.

You can always browse through the public projects section, there could be some projects there that are similar to what you’re invisioning

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