Struggling to select the right fin geometry and material, any tips ?

Hey folks, I'm working on a project involving the design of a heat exchanger, and I've hit a bit of a wall. I'm trying to optimize the fin design for maximum thermal efficiency while keeping the pressure drop within acceptable limits. I know the general principles, but I'm struggling with the specifics of selecting the right fin geometry and material.

Any tips or resources you could recommend for tackling this?

Appreciate any advice from those who've been down this road before!