Pressure wave supercharger

The Greenpeace SmILE concept car uses a Hyprex pressure wave supercharger developed by the Swiss company Wenko AG.

As the cell rotor continues to rotate and reaches the aperture on the inlet side, the compressed air flows to the engine (3).

The exhaust gas exits at high speed, sucking further intake air into the cell behind it, repeating the process (1).

It combines the advantages of mechanical and exhaust gas supercharging, offering ample torque at lower engine speeds.

One, that the exhaust gases intermingle with the fresh air needed for combustion, leading to some recirculation of burnt gas.

U.S. patent 4,563,997, Figure 1: Pressure wave supercharger
The four cycles of operation of the pressure wave supercharger.