Abstract: A gas dynamic wave machine or gas dynamic pressure exchanger for a supercharged internal combustion engine with the wave machine including a rotor or cell wheel driven by an independent drive arrangement. A charging air line is interposed between the gas dynamic wave machine and the respective cylinders of the internal combustion engine with the charging air line being selectively opened and closed in dependence upon an operative state of the internal combustion engine. A device is provided for delaying an opening of the charging air line for a predetermined time interval following a starting operation of the internal combustion engine. The independent drive arrangement for the wave machine is constructed as a hydrostatic drive device.