Forced Convection_Fan Impinging on Pin Fin Heat Sink

[pwilkins]

I have an analysis where fans are impinging on pin fin heat sinks.  For the electrical components sinked to this pin fin heat sink, I am getting temperatures that are 4-7 degrees hotter than empirical temperatures.  Assuming my heat input boundary conditions are correct, is it fruitful to really tighten up the mesh on these pins?  At the moment, the automatic mesh has only 3 nodes around the circumference of a 0.125" diameter pin.

I am asking rather than just running it because this system-level analysis will take ~13 hrs to run.

[Royce_adsk]

More mesh will help allow more air to flow through the heat sink which would allow the temperature to drop.

One thing to do sometimes with pin fin heat sinks is to accept that you aren't going to have a perfect circle.  Instead of making circular fins make X sided polygons so you can control the amount of mesh around the fins with more ease.  3 nodes around the pin is not enough.

Cheers,