I'm trying to determine the feasibility of a project, but have not yet taken fluid dynamics (next quarter). I'm trying to figure out how much power could be produced with a CO2 powered turbine. The turbine will be activated for only a few seconds at a time, with speeds under power ranging from 5,000-40,000 RPM. The turbine will see speeds up to 80,000 RPM. The goal of the project is maximum torque/power possible for the few seconds it will be activated. The CO2 will be injected at pressures ranging from 870psi to whatever I can achieve with entropy addition via a heat exchanger @ 230F. It seems the high head, low volume nature of the injected CO2 would dictate a pure impulse type turbine, or maybe an impulse/reaction turbine. My first thought was to make a sort of simple aluminum Pelton wheel type turbine, or use a turbocharger turbine with a custom housing to act as an impulse turbine with reaction turbine benefits. I will probably be using at least two nozzles, and the turbine diameter would have to be 4" or smaller. I have very little experience with this type of design problem, so any advice or text recommendation would be very helpful.