Heat Exchanger Modeling in COMSOL - How to Give Heat Flux at Wall?

[psidhu]

Hi

I am trying to model a 3D shell and tube heat exchanger where heat is transferring through the tube wall. For some purpose i have taken the wall thickness to be negligible so i have to give the heat flux at the wall in addition to heat conduction. I have endothermic reaction inside the tube and exothermic reaction in the shell so it is difficult to calculate the heat transfer coefficients.
As there are many options in comsol to give the heat flux at the wall. Is there anyone who can suggest how to give the heat flux at the wall?

 

[mmwave]

Hello,

Thank you for reaching out for help with your heat exchanger model. It sounds like you have a complex system with both endothermic and exothermic reactions. In order to accurately model the heat transfer, it is important to consider the heat flux at the wall.

One option for determining the heat flux at the wall is to use the heat transfer coefficients. These coefficients take into account the thermal properties of the materials involved and the flow conditions. However, as you mentioned, it may be difficult to calculate these coefficients in your system.

Another option is to use the boundary conditions in COMSOL to specify the heat flux at the wall. You can define the heat flux as a function of temperature, or use an external heat source to simulate the reactions inside the tube. Additionally, you can use the boundary conditions to account for the thickness of the tube wall, as you mentioned it is negligible in your model.

I would also recommend checking the COMSOL user guide and forums for specific examples and guidance on modeling heat exchangers. You may also consider consulting with a heat transfer expert for further assistance with your model.

Best of luck with your research and please don't hesitate to reach out for further help or clarification.