Patent ID: 8550057

Claim:
A supercharger comprising: first and second supercharger rotors disposed for rotation in the supercharger and each having a plurality of lobes configured to move air from an inlet to an outlet of the supercharger; an inner chamber defined in each of the plurality of lobes and configured to terminate at a lobe end opening; a perforated end face partially closing each lobe end opening; a plurality of ports extending through each perforated end face and supporting an oscillating air mass therein; a damping air mass in each inner chamber, adjacent to and in fluid communication with the oscillating air mass within each port of the plurality of ports, the damping air mass damping the oscillating air mass, thereby attenuating sound generated by the supercharger at at least one predetermined frequency based on a shape and configuration of the plurality of ports, wherein a length and a diameter of each of the at least one port is configured to attenuate a desired sound frequency.