Crossed Flow Intake

[pezman]

It's pretty easy to make little jigs out of lexan and wood that can be used as 2d flow simulators.

Depending on what you are testing, you can sometimes run a simulation using a steady-state flow. In other cases, you might need to simulate a combustion cycle (the jig can probably survive a single-cycle event in most cases).

I imagine that in some cases, you need an axi-symmetric model and need to go the full-tubular-monty and may even need to fabricate in metal, but I think that you can learn a lot using simpler models (e.g. your straw idea that was posted earlier).