Abstract: In a multiflow gas-dynamic pressure-wave machine, with a rotor, a housing surrounding the rotor as well as an air housing and a gas housing with ducts for the intake and discharge of the gaseous working medium, the cell ring of the rotor is subdivided by two intermediate pipes placed between a hub pipe and a shroud band into three concentric flows. The radially directed cell walls of the flows are mutually offset by one third of a cell division in the circumferential direction. The cells of the three flows in the circumferential direction have an uneven division.

Abstract: In a free-running pressure wave supercharger driven by the gas forces, nozzles (27) are provided in the gas casing (6) and possibly also in the air casing (5), which nozzles are connected--via a drive line (26)--with a position in the air casing (5), preferably with the high-pressure air port (2), at which position a surplus pressure relative to the nozzle entry occurs during the run-up phase of the pressure wave supercharger. A control device 15 actuates a supercharge air flat (14) in the port (2) and a valve device (23+25) in the drive line (26) in the opposite sense, i.e. if the supercharge air flap (14) holds the port (2) closed, the valve device (23+25) frees the flow through the drive line (26) to the nozzle (27) and vice versa. The diaphragm capsule (17) of the control device (15) is subjected, on one side, to the pressure in a compression pocket (11) via a control pressure line (19) and, on the other side, to the pressure before the supercharge air flap (14) in the port (2).

Abstract: Whereas the total noise level of an internal combustion engine supercharged by means of a gas-dynamic pressure-wave engine (1) (PWS) is usually only slightly higher than that of an engine supercharged by means of an exhaust-gas turbo supercharger (ETS), the narrow-band noise in the PWS rotational sound frequency range, the so-called PWS "whistle", is considered troublesome. The absorption muffler (3) is an elongate body, the length (l.sub.1) of which is at least 10 times the rotor outside diameter of the PWS. The inside diameter (d) of the muffler (3) corresponds to the inside diameter of the exhaust pipe (4) and is at least 0.6 times the rotor outside diameter of the PWS. The thickness (S) of the insulating material, which directly surrounds the inside diameter (d) or inner cross-section (F) of the muffler (3), is at least 6 times the rotor outside diameter of the PWS divided by the number of cells of the PWS.

Abstract: A control apparatus for a gas dynamic pressure-wave machine for charging combustion engines. The inflow cross-sectional area of the gas pocket in the high-pressure exhaust channel is controlled in accordance with the desired operating conditions of the engine by a bimetallic flap or valve member as a function of the temperature of the high-pressure exhaust gas.