I'm working on conjugate heat transfer simulations where the key output is the peak temperature of a solid component cooled by surrounding airflow or coolant. The challenge is that the predicted hotspot temperature is sensitive to how well the mesh resolves the solid-fluid interface and the near-wall region.
I wanted to share the approach I've settled on and hear how others here handle it:
- Monitor a single scalar (peak solid temperature) rather than judging convergence visually.
- Run progressively refined meshes (coarse, medium, fine) and plot peak temperature against cell count.
- Prioritize the boundary layer at the interface. Adding inflation or prism layers and checking the y plus target usually affects the result far more than refining the bulk mesh.
- Identify the plateau. The converged mesh is the coarsest one where further refinement shifts peak temperature by less than about 1 to 2 percent.
A couple of questions for the community:
For thin fluid gaps (closely spaced components or channels), what inflation-layer setup has given you reliable interface temperatures without exploding the cell count?
For transient runs, how are you balancing timestep against mesh fidelity to keep solve times manageable?
Interested in how others approach the accuracy versus cost balance for thermal CHT cases.
