[Michiel D]

Hi everyone,

I’m currently working on my master’s thesis, where I need to investigate which wheel design dissipates heat best using CFD analysis. I’ll have a CFD course in the first half of next year, but since this is my first encounter with CFD, I requested recordings from the COVID period to learn earlier. Unfortunately, this hasn’t solved my issues.

In essence, I need to simulate airflow (50 km/h) over a rolling cylinder/wheel (diameter 200 mm, thickness 62 mm) to determine heat flux through the surfaces. After struggling with the software, I asked a PhD student for help. He suggested a smaller domain, laminar flow, and a mesh of max. 500,000 elements.

While running the simulation, the residuals don’t explode but also don’t converge. I noticed large residuals near the free-stream boundary (mostly at the inlet), in the wake of the wheel, and near the stationary/rotating mesh interface.

What I tried:
- Mesh refinement
- Changing time step
- Adjusting inner iterations
- Switching turbulence models
- Changing domain size
- Modifying boundary conditions
- ...

I’ve been working on this for weeks without success. It seems like a simple problem, but my limited experience makes it challenging. Unfortunately, my contacts are too busy to help in a reasonable time.

I would really appreciate any advice or guidance!

Thank you in advance.