Fluid pulse surge control indicator

Claim 1

A COMPRESSOR STALL SENSOR COMPRISING: A SELECTED COMPRESSOR BLADE LOCATED IN A STREAM OF COMPRESSOR AIR FLOW; SAID BLADE HAVING A GENERALLY AIRFOIL SHAPE ALONG A CHORDAL SECTION DEFINING A LEADING EDGE EXTENDING FOREMOST INTO SAID AIR FLOW STREAM, A TRAILING EDGE DISPOSED HINDMOST IN SAID AIR FLOW STREAM, A CONVEX SURFACE EXTENDING FROM SAID LEADING TO SAID TRAILING EDGE INDUCING LOW PRESSURE AIR STREAM FLOW ADJACENT SAID CONVEX SURFACE, AND A CONCAVE SURFACE EXTENDING FROM SAID LEADING TO SAID TRAILING EDGE AND SPACED FROM SAID CONVEX SURFACE; FIRST AND SECOND OPENINGS FORMED IN SAID CONVEX SURFACE OF SAID COMPRESSOR BLADE; SAID FIRST OPENING BEING SPACED TOWARD SAID LEADING EDGE ALONG A BLADE CHORDAL SECTION FROM SAID SECOND OPENING; FIRST PASSAGE MEANS FORMED IN SAID COMPRESSOR BLADE COMMUNICATING WITH SAID FIRST OPENING; PULSE GENERATOR MEANS OPERATIVE TO GENERATE A PERIODIC PRESSURE PULSE; SAID PULSE GENERATOR CONNECTED TO SAID FIRST PASSAGE TO TRANSMIT PERIODIC PULSES THROUGH SAID FIRST PASSAGE AND OUT SAID FIRST OPENING INTO SAID AIR STREAM OPERATIVE TO INDUCE A TRANSITORY AIR STREAM SEPARATION FROM SAID CONVEX SURFACE WHEN STALL IS IMMINENT TO THEREBY INDUCE A PRESSURE INCREASE ADJACENT SAID CONVEX SURFACE AND ALONG A CHORDAL LENGTH THEREOF; SECOND PASSAGE MEANS FORMED IN SAID COMPRESSOR BLADE COMMUNICATING WITH SAID SECOND OPENING OPERATIVE TO RECEIVE AN OUTPUT PRESSURE SIGNAL INDICATIVE OF IMPENDING STALL.