Contact thermal conductance

[qq9481]

Hi,

My simulation is coupled temp-displacement analysis which consist of two parts.

Part1 penetrates Part2 and makes elastic-plastic deformation,heat transfer and then detached.

Simulation runs very well.(when i use arbitary contact thermal conductance value)

Problem is that I don't know how to calculate contact thermal conductance.

Could anybody let me know how to calculate that in below condition?
1. thermal conductivity of two parts is A and B respectively
2. contact has perfect contact surface(no voids at the interface, surface waviness, and surface roughness, etc)
3. pressure effect can be ignored.

thanks.

 

[DanStro]

I did some searching a while back for something similar and based on what I found it sounded like this needs to be measured, there is no analytical way of determining it.

 

[corus]

For perfect contact I'd expect the thermal conductance to be as heat flow across a material boundary. What thermal resistance would incur? ie. with a surface roughness you'd expect partial thermal contact, varying with pressure, and with some heat flow via radiation across voids which increased as the pressure decreased.

Tara

http://tinyurl.com/4ydjg7m

 

[mvp23]

I had faced a similar situation while doing a fully coupled analysis. I just assumed perfect contact , did a thermal resistance network analysis to help me find the temperature values. Abaqus calculates gap conductance as hgap =q/deltaT . Knowing the calculated temp values and since my problem involved a heat flux load , I was able to back out a gap conductance value. At least this way I came closer to an expected gap conductance value than use some random number. Also , if you specify a gap conductance value that is very low , then you will face convergence problems.