Airfoil Modification for Heat Transfer & Dissipation


#1

Hi I am doing my academic research/thesis on enhancing and modifying extended fin surface for heat transfer and dissipation. So in my modified design I have given the tip of the fin an airfoil shape in place of flat tip. My conception is for forced convection, whether its a laminar or turbulent air flow the air velocity at the top of the fin would much higher due to the boundary layer separation occurred on the top of the airfoil which would increase the heat transfer and would require less time to dissipate the heat.
Now my question is-

  1. Is my theoretical conception valid on using airfoil on heat transfer fro fins.
  2. Should I use conjugate heat transfer analysis for airfoil tip rectangular fins.
  3. I am actually having some problem in setting up the fin geometry in the Flow region. So it would be very helpful If the simscale support team experts can fix the geometry problem and guide me further.

I have followed this project for my geometry preparation and orientation:
https://www.simscale.com/projects/dzivkovic/fine_cht-rectangular_fins_ref_2

My project:
https://www.simscale.com/workbench/?pid=5665436301269066017#tab_0-0

Thanks In Advance


#2
  1. I would think that, at virtually any angle of attack, a ‘rectangular’ airfoil would have more boundary layer separation than any airfoil section. Conversely, I would think perhaps that small holes in a rectangular fin would create an even more turbulent separated boundary layer than without holes (depending on RN), certainly more surface area with holes. Am I missing something?

#3

Hi both,

With regards to the first pointer.

And with regards to what Dale has mentioned.

I agree with Dale. A rectangular fin may not be the best way due to possible BL separation at high enough flow speeds or Re, causing decreased cooling efficiency, however the scope of this effect is debatable especially for low flow speeds like in most consumer electronics. Inserting small holes on the other hand should help as surface area is increased. While turbulent effect from the holes will occur, again the magnitude of the effect may not be substantial.

I suggest running it nevertheless to see the magnitude of both effects. Keep in mind though that in practice, manufacturing costs need to be considered where obviously creating aerofoil shaped fins will be more costly. The key is to justify the cost of manufacturing with a significant increase in thermal performance which you probably have to find out.

Should be possible. Try it out!

What issues are you having? I checked the project and it is still at the geometry phase. Hasn’t been meshed yet.

Cheers.

Regards,
Barry


#4

Please make sure you post your results, I would be very interested :slight_smile: