Discussion Forum

I am trying to model heat transfer in a system. The system allows blackbody radiation and conduction. There is no convection as the open volume is a vacuum.

I am trying to verify my model by inspecting the energy budget.

the system is cylindrically symmetric. I am using the "derived values" to do line integrals and surface integrals and using the "compute surface integral" check box to turn the line integral into a surface integral and the surface integral into a volume integral.

When I try to add up the energies I am adding the radiative heat flux "ht.rflux" and the normal conductive heat flux ht.ndflux and expecting this to equal the deposited energy but it is not working out. What other form of heat flux am I missing?

I was trying different things and I saw there are components of heat flux. When I look at the radial component of the heat flux on a surface perpendicular to the axis there is a huge number. When I look at the magnitude of the heat flux it includes this number. What does this even mean. There should be no radial component of flux when the radius is in the plane of the surface. I also don't understand how comsol goes from radial and z components to magnitude. It isn't adding the components in quadrature so I don't know what it means.