Learning Forum

[Yifan Chen]

Hello everyone, I am using Fluent to simulate the cooling of a battery pack, using the most basic Realizable k-e model. I want to try to change the flow rate or temperature of the coolant. I would like to ask you, if I change these two conditions, what changes do I need to make to the boundary conditions? Do I need to modify the heat transfer coefficient? Or is the heat transfer coefficient automatically calculated by Fluent based on the boundary conditions, and I don't need to modify it?

[Rob]

Which heat transfer coefficient? Fluent will calculate any heat transfer between fluid & solid zones and you can report the HTC on those walls (read the definitions in the manual to understand what you're reporting). 

[Yifan Chen]

Thank you very much for your reply. What I want to consider is the Surface Heat Transfer Coefficient. I checked the guidebook and concluded that Fluent will automatically calculate the Heat Transfer Coefficient according to the boundary conditions (including the inlet temperature and speed of the coolant) during the simulation and apply it in the simulation. I don't know if my conclusion is correct. I hope you can enlighten me.

[Rob]

Fluent will calculate the heat transfer, and then can report the heat transfer coefficient for the wet walls. Note the distinction. HTC is a made up number to assist engineers in comparing designs where surface area/flow/stuff may be very different. 

[Yifan Chen]

Thank you very much for your reply, which is very helpful to me. I checked the data of Surface Heat Transfer Coefficient of one liquid cooling tube and found that my data only has data at one position. I don't know whether my data or settings are correct.

[Rob]

Does the tube axis align with the y-axis? 

[Yifan Chen]

Thank you very much for your reply. Are you referring to whether the axis of a cooling channel is aligned with the y-axis? If so, it seems that my axis is aligned with the x-axis.

[Rob]

If you're plotting on the inlet, which has only one value of x, why wouldn't you get the plot you're seeing?