THE HOT SECTION OF AIRCRAFT JET ENGINES

ERGO-TECH PROPOSES TO THE U.S. AIR FORCE THE DEVELOPMENT OF AN ONBOARD INFORMATIONAL SYSTEM TO CONTINUOUSLY MONITOR IN FLIGHT THE PATTERN FACTOR OF THE TURBINE INLET TEMPERATURE (TIT) OF JET ENGINES. THE SYSTEM CONSISTS OF AN ARRAY OF LOW COST RUGGED MINIATURE ACOUSTIC TRANSDUCTERS MOUNTED ON THE HOT SECTION ENVELOPE OF THE ENGINE. THE SIGNALS FROM THESE SENSORS ARE INPUT INTO A MICROPROCESSOR WHERE THEY ARE SUBJECT TO A CAREFULLY SELECTED SET OF ALGORITHMS SUCH AS SELECTIVE BAND DIGITAL FILTERING, HIGH ORDER SPACE/TIME CROSS CORRELATIONS, AND NUMERICAL INVERSIONS. THE APPLICATION OF THESE TECHNIQUES RENDERS AN IMAGE OF THE SOURCE DISTRIBUTION OF THE COMBUSTION GENERATED NOISE. THE DISTRIBUTION IS TIGHTLY RELATED TO THE COMBUSTOR PATTERN FACTOR WHICH IS IN TURN THE PRIMARY DRIVER FOR THE DEGRADATION RATE OF THE ENGINE HOT SECTION. THE CONCEPT IS A COMPUTER IMPLEMENTATION OF THE PILOT'S OLD TECHNIQUE OF LISTENING TO HIS ENGINE!