Help with thermal transmittance computation

Many · April 13, 2016, 05:20

Hi ANSYS Users,

I need to compute the thermal transmittance (aka U-value) on my geometry, a simple panel with a given thickness. I am using different materials.

Simulations are being performed with Steady State Thermal in ANSYS WorkBench.

U-value can be obtained as the ratio between the heat flow rate Q(W) through the whole area of the element and the product of the total area of the element with the temperature difference between external and internal bulk temperatures.

I am not used to work with thermal analysis, but I guess I need to obtain averaged values for heat flow rate through the area of the element. I cannot obtain it form Mechanical directly (using Probes or Reaction Probes I just get maximum and minimum values, not an average quantity).

Can anybody give me any hint to compute my transmittance? Can I do this using ANSYS Mechanical or the software have not enough capabilities to compute it directly? I am afraid, I have never used APDL, and this seems to be the only way...

Thanks in advance!

Tensian · April 13, 2016, 06:17

Hi Many,

I am also not able to obtain averaged variables on surfaces using Ansys MECHANICAL and I need to compute this U-value too.

Could anybody seed some light on this? It is weird that this complex software does not include this common feature for postprocessing...

Anyway, I will give a try to CFX.

Do you think this could be a suitable tool for solid thermal analysis?

Good luck Many!

April 13, 2016, 05:20	Help with thermal transmittance computation	#1
Many Member Liam Join Date: Aug 2013 Posts: 40 Rep Power: 12	Hi ANSYS Users, I need to compute the thermal transmittance (aka U-value) on my geometry, a simple panel with a given thickness. I am using different materials. Simulations are being performed with Steady State Thermal in ANSYS WorkBench. U-value can be obtained as the ratio between the heat flow rate Q(W) through the whole area of the element and the product of the total area of the element with the temperature difference between external and internal bulk temperatures. I am not used to work with thermal analysis, but I guess I need to obtain averaged values for heat flow rate through the area of the element. I cannot obtain it form Mechanical directly (using Probes or Reaction Probes I just get maximum and minimum values, not an average quantity). Can anybody give me any hint to compute my transmittance? Can I do this using ANSYS Mechanical or the software have not enough capabilities to compute it directly? I am afraid, I have never used APDL, and this seems to be the only way... Thanks in advance!

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April 13, 2016, 06:17		#2
Tensian Senior Member James Join Date: May 2013 Posts: 116 Rep Power: 12	Hi Many, I am also not able to obtain averaged variables on surfaces using Ansys MECHANICAL and I need to compute this U-value too. Could anybody seed some light on this? It is weird that this complex software does not include this common feature for postprocessing... Anyway, I will give a try to CFX. Do you think this could be a suitable tool for solid thermal analysis? Good luck Many!