|
[Sponsors] |
November 17, 2015, 02:35 |
Natural convection heatsink led module
|
#1 |
New Member
Join Date: Nov 2010
Posts: 23
Rep Power: 15 |
Hi,
I need to run a steady simulation of an aluminum heatsink in a volume of air (ideal gas) @fixed T at rest in order to calculate its T field and understand the flow field that originates externally thanks to natural convection. I set up the heatsink with regions considering the two PCB, the led (volume heat power source), some internal plastic components and the internal and external air. I set up Interfaces Contact In place to allow heat transfer. The external air is a big cylinder, and here comes the trouble. Which BC to be applied at the inlet and outlet circular surface of it? With Stagnation Inlet @gauge p = 0 and Pressure Outlet @gauge p=0 I obtain a FLOW FROM TOP TO BOTTOM. Why? That's the effect of gravity? But I expect a flow in the opposite direction, because air is going to be heated (so density is going to decrease). With the same inlet and free flow at outlet I obtain a flow correctly going from bottom to top. But in theory everything should go correctly also with the first set of BC. Any ideas? Thanks |
|
November 17, 2015, 02:36 |
|
#2 |
New Member
Join Date: Nov 2010
Posts: 23
Rep Power: 15 |
I forgot to say that's it's laminar.
|
|
November 17, 2015, 09:18 |
|
#3 |
New Member
Join Date: Nov 2010
Posts: 23
Rep Power: 15 |
No idea at all?
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Natural convection from heatsink | freefall | FLUENT | 1 | November 18, 2013 09:14 |
Thermophysical properties for natural convection | Ciefdi | OpenFOAM Running, Solving & CFD | 0 | November 7, 2013 11:44 |
natural convection problem with radiation | jorien | CFX | 0 | October 14, 2011 09:26 |
Can someone PLEASE document the development version installation | bernd | OpenFOAM Installation | 76 | November 14, 2008 21:51 |
Coupled vs Seg - Natural vs. Forced Convection | Alex | Siemens | 5 | December 12, 2007 04:58 |