Dual Fans - Inlet and Exhaust

Project Support
1

Hello,

My project is about Battery pack thermal management in which I was planning to include one air inlet and one air exhaust so in the simulation I wanted to include one inlet velocity and one outlet velocity, but this gave an error saying you need to have one BC as pressure outlet , and again when I did it with three BC’s velocity inlet, velocity outlet and pressure outlet it again gave an error saying multiple boundary conditions. So is there a way I can do this to have two fans.

Thank You in Advance

2

Hey @MukulBondade,
is it possible to post a projekt link here ? So that we can directly look into it.

Best regards
Kai

1 Like
3

This is the link to my project.
For now I’m running it with only inlet velocity and one natural convection BC.

Thank You.

1 Like
4

ok, i copied the projekt, thank you.

im trying it with a normal pressure outlet with 0 Pa pressure. I change the sim time to 100 seconds. The sim progress is about 50 % but i cant see a solver log or a con plot.
I think i will wait a bit longer and than look again.

If you like we can compare the results…

Best regards
Kai

5

Ok , thank you very much.
My simulation is actually running for 1800s.
So in this case you have three BC’s

  1. Inlet velocity
    2.outlet velocity
    3.outlet pressure (0pa).
    Am I right ?
6

So, my simulation is finished.
Here is the link SimScale

What does your simulation ?

Best regards
Kai

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7

Thanks,
I too have got similar results for using natural convection for outlet but my doubt is can we have one inlet velocity and one outlet velocity and one pressure outlet as BC.

Thank You once again.

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8

Hey @MukulBondade,
oke, that is good news. Yes, you can have your three suggested BCs, but not at the same area.

My question is, are the expected results different with a outlet velocity bc than an pressure outlet ?

Best regards
Kai

9

Hello @Kai_himself,

The results were similar in terms of Tempearture , but there was an interesting part, the Temperature Distribution however was not same in the two cases.
In the case with Outlet Velocity as BC the temps were much higher when compared with only Pressure Outlet as BC.
Can you please explain to why is it this way?

Here is the link,

Now I’m also currently running a simulation for Natural Convection as BC.
To compare the results.

Regards,
Mukul

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10

Hey @MukulBondade,
yes, you are right, the temperature distribution is not the same. Did you simulate in your first simulation 1000 iterations? These simulations are only calculated 100 iteratons. I think this is much to low, to reach a good convergence you need to calculate more iterations.

Best regards
Kai

1 Like
11

Hello @Kai_himself,
Yeah in the real testing I did run the test for 1800 seconds, for that I had used mesh fineness as 5, it was an intense calculation for the CPU I believe (Mine is a community account), the simulation ran for about 1200 mins step by step,
now I’ll reduce the mesh fineness to .5 and try running it again.
One last doubt, how did you assign the pressure outlet BC in your model,

For the pressure outlet condition the Circle is still Red.

Thanks and Regards,
Mukul

1 Like
12

Hey @MukulBondade,
oh that is easy :slight_smile: . I removed the velocity outlet and assign the pressure outlet.
Is there anything new at your simulations ?

Best regards
Kai

1 Like