The results of a modal transient analysis of the engine/aircraft system are presented. The response of the JT9D to analytically simulated vertical gusts and landings was predicted using a NASTRAN finite element mathematical model of the JT9D/747 propulsion system. The NASTRAN finite element model of the propulsion system included engine structural models of the fan, low/high pressure compressors, diffuser/turbine cases, and high/low pressure rotors, as well as nacelle models of the inlet cowl, tailcone, and wing pylon. The analysis conducted predicts that an insignificant level of JT9D-7 performance deterioration would occur due to a typical vertical gust encounter or a typical revenue service landing. Analysis of a high sink rate landing with a heavy fuel load indicates the possibility of local wear, however, the lack of an accurate dynamic rotor/seal interference model precludes an accurate quantitative evaluation of performance change for this once-per-airframe-life event.
Effect of Time Dependent Flight Loads on Jt9d-7 Performance Deterioration
1979
73 pages
Report
No indication
English
Jet & Gas Turbine Engines , Aircraft , Aerodynamic loads , Aircraft engines , Performance prediction , Propulsion system performance , Structural analysis , Nastran , Aircraft landing , Airframes , Finite element method , Gust loads , Mathematical models , Propulsion system configurations , Vertical air currents , T-9 engines , JT9D-7 engines