To detect a stall limit in advance by providing a sensor for detecting flow velocity or total pressure, directly behind a rotor blade, and detecting the stall limit from the waveform of sensor output.
A rotor blade 15 consists of a plurality of blades, and outlet air of the rotor blade 15 brings with it periodic flow velocity or pressure change blade by blade in one rotation of the rotor blade, and a sensor 16 detects this flow velocity or total pressure change with the lapse of time. This sensor 16 detects the flow velocity or total pressure of air compressed by the rotor blade 15. A stall limit is detected from the output waveform of the sensor 16, and before the generation of a part span stall, a solenoid valve 18 is opened to blow off air toward the rotor blade 15 from an air jet nozzle 17. The stall limit can therefore be detected in advance by observing flow velocity or total pressure change at the outlet of the rotor blade 15.
KUROSAKI MASAHIRO
UEHIGASHI ATSUSHI
