Best practices for resolving thin coolant gaps in conjugate heat transfer simulations of battery modules?

I’m setting up a conjugate heat transfer (CHT) simulation of a tightly packed prismatic battery module and running into the classic trade-off between mesh count and resolving the thin fluid gaps between cells and the solid-fluid interface.

A few points I’d be interested to hear the community’s experience on:

  • For the thin coolant channels between cells, are you getting reliable interface temperatures with prism/inflation layers plus a trimmed mesh, or has it been worth switching to a different meshing approach?

  • How many inflation layers (and what y+ target) have worked well for you at the cell-coolant interface before peak temperature stops shifting?

  • For transient duty-cycle runs rather than steady state, how are you balancing timestep size against mesh fidelity to keep solve times reasonable?

  • Anyone including busbar joule heating in the same model, or decoupling it as a separate step?

I generally run a mesh independence study tracking peak cell temperature until it plateaus, but I’d like to hear how others approach the same problem — especially what gave the best accuracy-vs-cost balance in practice.