I’m very curious about this “Comprex” pressure-wave supercharger. It’s a very interesting method of air charging (to me). Why was this device was only used in diesel engines?
There’s a great paper from Journal of Engineering for Gas Turbines and Power:
It summarizes development of wave rotors from the 1920’s through the Comprex and Hyprex devices right up to the Wave Disk Engine. The paper cites a vast body of existing research (as of 2006) in its reference section and concludes by saying, “Continued research on sealing and thermal expansion control are needed to solve these persistent challenges.” Beyond sealing and thermal expansion, I think contamination of intake charge with exhaust gas and the size of the device render it less useful to the automotive engineer than the compact and reliable turbo charger.
Read the paper carefully and follow the linked references to catch the nuances behind the technical discussion - especially on things like pockets.
Above is a snippet.