IMPROVED ROTARY, BLADED, CIRCUMFERENTIAL FLUID-FLOW MACHINES

1,237,363. Circumferential-flow compressors. NATIONAL RESEARCH DEVELOPMENT CORP. June 14, 1968 [March 29, 1967], No. 14356/67. Heading F1C. A circumferential-flow compressor has a rotor 3, Fig. 1, having blades 4 arranged within a toroidal passage 6 containing a toroidal guide 11 and communicating with the inlet 7 and the outlet 8. A partition 9 between the inlet and outlet is provided with an acoustic wave guide 12 into which high-pressure fluid trapped between the rotor blades by the partition is directed. The wave guide is tuned to resonate at the frequency at which successive or alternate blades move past the wave guide inlet for a predetermined rotor speed, to produce a standing pressure wave in the wave guide. The wave guide communicates, via duct (13), Fig. 2 (not shown), with the toroidal passage 6 at a position preferably diametrically opposite the partition 9 to return the fluid to the passage at about the mean pressure therein. The passage may decrease in cross-sectional flow area from the inlet to the outlet and may contain stator vanes 15, 16, Fig. 3. The rotor blades and stator vanes may be of aerofoil form.