A COMPUTATIONAL MODEL FOR THRUST REVERSING AND VECTORED JETS

BECAUSE OF RECENTLY DEFINED TACTICAL THREATS IT IS DESIRABLE TO IMPROVE THE MANEUVERABILITY AND TAKE-OFF/LANDING ASPECTS OF AIRCRAFT PERFORMANCE. IT HAS BEEN DETERMINED THAT SUCH IMPROVEMENTS CAN BE ACCOMPLISHED BY THE USE OF THRUST REVERSERS OR VECTORED JETS. IN ORDER TO DESIGN AIRCRAFT SATISFACTORILY IT IS NECESSARY TO HAVE A PREDICTION METHOD THAT IS SUFFICIENTLY ACCURATE. THE MOST DIFFICULT FLIGHT REGIME TO PREDICT ACCURATELY IS THE LANDING CONFIGURATION WHEN THERE ARE HOT GAS JETS IMPINGED ON THE GROUND CAUSING COMPLEX AERODYNAMIC PHENOMENA THAT CAN CRITICALLY AFFECT STABILITY AND CONTROL OF THE AIRCRAFT. PREVIOUS RESEARCH HAS INDICATED THAT ACCURATE MODELING OF THE TURBULENCE IN THE FLOW IS CRITICAL. THIS PROPOSAL IS CONCERNED IN PHASE I WITH IDENTIFYING THOSE AREAS WHERE EXISTING TURBULENCE MODELS ARE INADEQUATE AND ASSESSING THE IMPORTANCE OF THESE AREAS TO THE ACCURATE PREDICTION OF THE AIRCRAFT STABILITY AND CONTROL.