Hello all, I am trying to figure out what my convection coefficient for a microprocessor might be. What number should be substituted for m^2 in the equation (W/m^2)K? Also my other question is a two part question. Part A) What is the difference between the temperature load and the ambient bulk temperature. Part B) For most applications would they not be the same? Thanks in advance guys.
So in table natural air convection is anywhere between 5-25. I am trying to figure out for a temperature of say 75 F. What convection coefficient would I use from that 5-25 range? And how would I figure that out.
flow simulation!
the 5-25 is based on everything from fluid temp to fluid pressure to fluid composition
if you're cooling something, go with 25 which is worst case, heating something, go with 5 which would be worst case
in flow simulation you could just apply the conditions of the temp and the output would be the convection coefficient
Jared- going back to the coefficent. Using regular solidworks thermal simulation not flow. It asks for the convection coefficent when applying a convection load to a part say aluminum. Now you can easily find this online. Is this the number I would put in there? The reason I ask is because if this is the case wouldnt this be something that solidworks could pick up from the part and the material that you assigned it before you started this flow simulation? Thanks for the help Jared.
the material properties related to thermal are thermal conductivity and heat capacity, those are picked up based on the material you apply
convection coefficient is relative to the environment, fluid temp, fluid velocity, type of fluid, pressure...etc, so it really isn't related to the material which is why it doesn't get picked up based on the material.
Correct this was my original train of thought I just wanted to make sure I was on the right. I am just having real troubles get my simulation to give me any viable results. I have posted a little thermal test that I have been trying to get to work. If you dont mind would you mind checking it out, and letting me know what could be done or setup differently. Thanks in advance for the help.
I don't think your model got posted.
But checking the simulation for accuracy comes down to having a detailed description of the test conditions.
Generally when results don't match physical, the issue is that the boundary conditions aren't matching physical. That is where I would focus efforts.
convection coefficient will be relative to the environment
temp load > temp is applied
bulk ambient temp > temp for the convection calc
why won't they be the same > convection is less "effective" than something being at a temperature
check this, should cover all your questions:
2012 SOLIDWORKS Help - Convection Heat Coefficient