Centrifugal supersonic compressor

Claim 1

A centrifugal compressor which is supersonic at rated output, said compressor comprising in combination: a stator, a rotor mounted for rotation about its axis within said stator, said rotor being in the form of a drum and including spaced opposed discs whose similarly curved inner surfaces relative to each other define therebetween a gas flow path which changes from axial to radial, a plurality of circumferentially spaced blades carried by said rotor and extending between said rotor discs from the vicinity of the compressor axis throughout that portion of the flow path which changes from axial to radial, said discs having their periphery extending radially outward beyond the outboard edges of said blades to form disc extensions defining a rotary diffuser, and wherein the mutual radial dimensions of the blades of the discs are such that the speed of the compressed gas at the outlet of the rotating diffuser is slightly supersonic at rated output, said stator including a fixed diffuser positioned as an extension to the rotary diffuser in a direction of a gas flow which is to be compressed, said fixed diffuser comprising a vaneless volute circumferentially surrounding said rotor and a rectilinear diverging nozzle connected tangentially to said volute, said vaneless volute having a peripheral spiral wall of continuously increasing diameter leading to said nozzle, and said nozzle having a sonic inlet means at the end of said volute at rated compressor output, whereby; a recompression shock wave is caused in the flow of the gas in the vicinity of the connection of the nozzle to the volute.