SimScale CAE Forum

Problem with results (heat transfer)

Hello everyone.

This is my first simulation here. I try to simulate a heat tranfer between a heat surce and a water cooled copper profil. The value for the heat source is 4000W. The water speed ist 0,75m/s. (400l per hour)

The temperatur diffrence between inlet and outlet is just 1 degree. Thats to low. (something around 9 degree would be right) The heat source has also a to low temperture.

I thing a have i bug in my workflow.

https://www.simscale.com/projects/rwaize/heat_transfer_1/

Hey there, and welcome to the forum!

I agree with you that results don’t look ok. I would expect a higher temperature drop on the fluid.

Here are some aspects that I would improve:

  • The copper material might have too low conductivity, please try different values for this parameter.
  • Finer mesh, especially to better capture gradients across the thin wall of the heat source and the fluid duct.
  • Allow to run for more iterations, so that residuals can get lower (2k to 3k is a good starting point). Below 1e-3 for the highest residual should be acceptable.
  • Try the Conjugate HT v2.0 solver.

I will tag here my colleague @RicardoParis who might be able to give deeper insides in the physics.

Hi,

CHTv2 would definitely help here with convergence. On a side note: it’s very likely that the simulation results are not yet converged.

I’d highly encourage you to set result controls, especially an area average at the outlet. From the residuals alone, I cannot tell for sure if the parameters of interest are still shifting.

This page should provide you more insights: How to Check Convergence of a CFD Simulation? | SimScale

Cheers

Thanks for your answer.

I done a new project. https://www.simscale.com/projects/rwaize/heat_transfer_v2/

The result in the post process looks better. I think i need some additional iterartion to improve the result.

In the post process i want to check the surface statistic. But i can only pick the volume of the model.
I did reset the result view and reset the solution field.

Hi,

Have you already tried hiding all cell zones and only maintaining the walls (i.e. default region) visible?

It should allow you to select faces.

Cheers

ah …that works

Thanks very much.