Patent ID: 7765993

Claim:
An inlet apparatus for a compressor having a housing defining a generally C-shaped inlet opening and a rotor cavity configured to contain interleaved, counter-rotating first and second rotors, the inlet apparatus comprising: an inlet duct positioned upstream of the compressor defining an inlet opening and a generally C-shaped outlet opening; wherein said inlet duct has an inner wall defining a cavity operable to communicate airflow between said inlet opening and said generally C-shaped outlet opening of said inlet duct; wherein said generally C-shaped outlet opening of said inlet duct is substantially similar to the shape of the generally C-shaped inlet opening of the housing; wherein said inner wall includes a floor portion and a roof portion, said floor portion and said roof portion extending from said inlet opening to said outlet opening of said inlet duct; and wherein at least a portion of said floor portion is contoured to impart a velocity component to said airflow complementary to the tangential velocity of each of the first and second rotors during rotation of the first and second rotors.