EvaluateHeatRate Matlab PDE units and discussion

Dear community,

I am using the PDE Toolbox, thermal model. I am interested in knowing the heat flux on a given face of my 3D geometry.

I tried to use EvaluateHeatFlux first, but it looks unsuitable for evaluations on a plane of a 3d geometry, unless some thickness is also provided (I might be wrong, please correct me).

Then I tried to use EvaluateHeatRate on the target face as follows:

Qn = evaluateHeatRate(thermalresults,'Face',2);

My question is: what is exactly the difference between heat flux and heat rate? What is the unit of measure of the heat rate according to matlab PDE?

I thought it represented the Watts emitted by the face, therefore to get the heatflux I just had to divide it by the surface area, but it returns weird results.

Can anyone help me please?

Thanks

Answer 1

[Ravi Kumar]

evaluateHeatRate returns the value of heat flux integrated our the specified face. So its unit would be unit of enery, if everything was set up in consistent SI units then that woud be W. Heat flux on the other hand is distriburted quanity, hence its units would be W/m^2.

So dividing the heat rate by area to get heat flux is correct. What do you mean by you get weird result? Can you give an example?

Regards,

Ravi