Learning Forum

[Abraham Plis]

Hello,

I am attempting to simulate a heat exchanger in Fluent and am having difficulty. One side of the HX has a -100 W/m2 known heat flux and the other sides of the HX are adiabatic. Flow is coming into the inlet at 0.053 m/s and 20 C. The flow should exit at a temperature 5 degrees lower due to the heat flux but the temp is staying near constant in my model. What am I doing wrong??

I have the inlet and outlet conditions specified, materials selected properly, and the BCs on the walls have been specified but there is still no heat transfer occurring from the fluid. Are there any common mistakes that I might be making with this simulation? 

[C N]

Hello Abraham,

I would recommend you to use the heat exchanger model that is already specified in fluent . This could make your workflow easier and also help you achieve your desired results. 

There are many heat exchanger model . I am attaching the link where they would have mentioned on which is the model you have to choose according to your requirements and also on how to set up and model the simulation according to best practices. Kindly follow this user guide link.

15.5. Modeling Heat Exchangers (ansys.com)

I hope this helps you in modelling heat exchangers accurately .

Thanks,

[Abraham Plis]

Here are some photos of what I am working with now. It appears that the fluid is not interacting at all with the solid domain in the contour plot I have established. What might be the cause for this?

[C N]

Hello Abraham,

By looking at your contour, for the fluid not interacting with the solid domain the following reasons can be causing it.

1) I would recommend you to check the whether you have used the share topology feature in the cad level creation of the model. 

2)I would suggest you to send me your mesh pic if it is non-conformal between different solid and fluid zones then you have to create an interface for non-conformal mesh.

3)I would recommend you to use the watertight geometry workflow for meshing with the best practices and set the domain and boundary condtions of the domain correctly there. It will lead you to create the cell zone and boundary conditions accurately when you switch to solution mode from meshing mode.

I am attaching the user guide link for you reference on how to create interfaces for non-conformal mesh

6.6. Non-Conformal Meshes (ansys.com)- Check the coupled wall option.

These could be the following reasons. Kindly check them form your end. Hopefully this should solve your problem. 

Thanks,