AIRFLOW MONITOR AND STALL WARNING DEVICE

THIS PROPOSAL IS A REQUEST FOR AN EVALUATION OF AN AIRFLOW MONITOR AND STALL WARNING DEVICE ON A HIGH PERFORMANCE AIRCRAFT EXHIBITING THE CHARACTERISTICS OF A MODERN JET TRANSPORT. THE DEVICE PROVIDES A METHOD OF SENSING LOCAL AIRFLOW PHENOMENA OVER AN AIRCRAFT WING, INCLUDING THE TRANSITION FROM LAMINAR TO TURBULENT FLOW, AND USING THIS PHENOMENA TO PREDICT THE APPROACH TO A STALL. THE DEVICE EMPLOYES A HOT-FILM ANEMOMETER TO SENSE TOTAL LOCAL AIRFLOW VELOCITY. THE TOTAL AIRFLOW VELOCITY IS THEN REDUCED TO TWOCOMPONENTS; THE TIME AVERAGE VELOCITY FIELD (U) AND THE ROOTMEAN SQUARE VELOCITY FLUCTUATIONS (URMS). THE RATIO OF THESE COMPONENTS (URMS/U) HAS A SIMPLE CORRESPONDENCE TO TURBULENCE INTESNITY WHICH, IN TURN, IS RELATED TO THE STALL OF AN AIRFOIL. THE SIGNIFICANCE OF THIS SYSTEM IS THAT IT PROVIDES A DIRECTMEASURE OF THE LOCAL AIR VELOCITY OVER AN AIRFOIL, AND CAN THUS SENSE TURBULENCE PRECEEDING A STALL REGARDLESS OF THE STATUS OF THE WING, I.E.-ICE OR FROST, LEADING EDGE SLATS UPOR DOWN, OR ANY CONDITION THAT CHANGES THE NORMAL AIRFOIL SHAPE. IT IS A DIRECT MEASURE OF STALL CONDITIONS COMPARED TO SECONDARY DEVICES SUCH AS ANGLE-OF-ATTACK OR STAGNATION POINT SENORS. THE PURPOSE OF THIS TECHNICAL PROJECT IS TO EVALUATE THE HOTFILM ANEMOMETER TO ALLOW DETERMINATION OF THE PARAMETERS NEEDED FOR A SENSOR PROVIDING THE SAME QUANTITIES, BUT MORE RELIABLE IN OPERATIONAL USE. THE SECONDARY PURPOSE OF THE PROJECT IS TO GATHER PILOT COMMENTS ON THE DISPLAY TO PROVIDE DATA FOR ANALYSIS TO DETERMINE THE OPTIMUM METHOD OFDISPLAYING THE INFORMATION TO THE PILOT.