Radiators in Therm

[Ben K]

Hi everyone,

I am new to THERM and wanted to see if it was capable of capturing the effects of adding a radiator on the inside window glass temperature. I defined this by drawing a box to represent the radiator and defining a boundary condition on the top of the box with a constant heat flux. I am getting some very hot temperature near the radiator, but it quickly changes to more reasonable temperatures. I am wondering if this is a good way to approximate the overall effect of the radiator on the glass temperature. I have attached some pictures. 

Thank you!

[yal...@gmail.com]

Hi Ben,

you need to turn on the interior gray body radiation because you have this large flux coming in but is not being redistributed by radiation away. Also the air film coefficient is for still air and you will need to calculate it for a radiator.

Also if your radiator or fin tube output is 960Btu/ft2 you need to factor in the area of the perimeter of the radiator in the model. i.e. if the perimeter is 1.5ft then the actual input into the model will be 1.5 * 960.

In reality there will be an air gap between the fin tube body and enclosure and the boundary condition should be applied to the internal part of this which you can't do therefore making Therm not ideal to model this type of condition. However if you account for some of these by manual calculations you should be able to apply the right boundary condition to simulate this.

Yalin