TUBROSHAFT ENGINE SURGE CONTROL

THE SUBJECT OF THIS SBIR PROPOSAL IS THE DETECTION AND CONTROL OR ELIMINATION OF COMPRESSOR STALL/SURGE IN U.S. ARMY HELICOPTER GAS TURBINE ENGINES. STAFF OR SURGE CAN LEAD TO POWER LAPSES AND POTENTIALLY DESTRUCTIVE STRUCTURAL LOADS. RECENT R&D IN VARIOUS CENTERS SHOWS PROMISE FOR ACTIVE COMPRESSOR CONTROL. SUCH CONTROL WOULD EXTEND OPERATION INTO THE PREVIOUSLY FORBIDDEN SURGE REGION. THIS WOULD IMPROVE ENGINE EFFICIENCY WHILE ELIMINATING OR MITIGATING STALLS AND SURGES IN COMPRESSORS. ACTIVE COMPRESSOR CONTROL CAN BE ACHIEVED BY A DIGITAL FEEDBACK CONTROL LOOP SENSING STALL INCEPTION VIA PRESSURE TRANSDUCERS, AND USE OF ENGINE VARIABLE GEOMETRY, BLEED, OR FUEL MODULATION OT STABILIZE COMPRESSOR AERODYNAMIC FLOW. SUCH A LOOP REQUIRES DETAILED MODELING OF THE COMPRESSOR STALL AND ACTUATOR CONTROL MECHANISMS. THIS PHASE I PROPOSAL USES NEW THEORETICAL AND EXPERIMENTAL RESULTS TO DEVELOP A SYSTEMS APPROACH AND PRELIMINARY DESIGN OF A SURGE CONTROL LOOP FOR A HELICOPTER GAS TURBINE ENGINE. ALSO, A TRADEOFF ANALYSIS INVOLVING SURGE PROTECTION AND ENGINE BENEFITS IS DEVELOPED. THIS PHASE I STUDY HAS THE ULTIMATE GOAL OF DESIGN AND TEST OF STALL CONTROL LOOP HARDWARE IN PHASE II FOR A DESIGNATED ENGINE.