Neat stuff. I remember years back reading the patent on a turbo compressor that had no moving parts and and relied on vortices and boundary layers between intake and exhaust. Made 40 psi without mixing the gases without any physical barrier. I think it likely had start up and variable load issues and only worked at a set runn8ng rpm and load. I used to inspect the propellers on boats, and you can read the prop by the damage caused by cavitation behind the leading edge on the vacuum side. Vortices are fun, the victor shawberger (sp?) discoveries with water vortices are fascinating, and his air ones are mind boggling neat. Care to say what the project is?