Heat flow and natural convection heat

Using SimScale
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Screenshot 0-2
Screenshot 0-21729×1297 130 KB
Screenshot 0
Screenshot 01729×1297 397 KB

hi , im Aiden from Korea

I have some question about SimScale simulation.

picture 1 is using heat flow and picture 2 is using conjugate heat transfer.

When the air flows, I try to see if the temperature of the device drops.

I gave same value : volume heat flux (3000000 w/m^3)

picture 1 said that the temperature is 35.15 ’ but when air flows( picture 2) it said that the temperature is over 70 ’

1.what is problem about this simulation? and how to fix it to solve correct temperature in this simulation?

  1. How many values do I need to put in to apply 3 watts to the instrument?

thank you.

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picture 1 is rdp370fr - die heat for 0.8t big al volume- run2

picture 2 is rdp370f heat - Conjugate Heat Transfer v2.0 2 - run 3

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Hey Aiden, thank you for sharing! These simulations have the exact same geometry, right?

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yes, that’s right! @tsite

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Hey Aiden,

In the heat transfer simulation (first image), you’ve set the convective heat flux (boundary condition) with covective coeff (h) as 50, which is too high to be achieved by a natural convection cooling technique. Values of h achievable by natural convection lie roughly between 1 to 30 W/m2 K.
Hence in the second simulation (conjugate heat transfer) when you setup natural convection cooling, you are getting higher values of temperatures as cooling is not that effective.
You may want to setup some sort of forced convection cooling, to lower the temp values.
Cheers!

2 Likes
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hi Simrnjandu
thank you so much to reply my question. It really helped me a lot.

thank you

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You’re welcome!