ZONAL METHOD FOR MODELING POWERED-LIFT AIRCRAFT FLOW FIELDS

ADVANCED SHORT TAKEOFF/VERTICAL LANDING AIRCRAFT ARE DESIGNED TO USE EXHAUST JETS TO DIRECTLY INCREASE LIFT. BEING ABLE TO NUMERICALLY MODEL THE FLOW FIELDS INVOLVED IN THESE DESIGNS WOULD GREATLY IMPROVE THE DESIGN PROCESS. THEPROPOSED EFFORT IS TO DEVELOP A COST EFFECTIVE FLOW ANALYSISTOOL FOR MODELING POWERED-LIFT AIRCRAFT FLOW FIELDS. THE PHASE I OBJECTIVE IS TO DEMONSTRATE A ZONAL METHOD THAT WILLFROM THE BASIS FOR A DESIGN TOOL. BY DIVIDING THE FLOW DOMAIN INTO ZONES AND USING THE APPROPRIATE FLOW ANALYSIS CODE IN EACH ZONE, AN EFFICIENT NUMERICAL PROCEDURE WILL BE DEVELOPED. OPTIMAL TECHNIQUES FOR SIMULTANEOUSLY COUPLING THE ZONAL SOLUTIONS TO PROVIDE A CONVERGED OVERALL SOLUTION WILL BE DEVELOPED. INITIALLY, A 3D NAVIER-STOKES CODE MODELING THE VISCOUS FLOW FIELDS WILL BE COUPLED TO A POTENTIAL FLOW CODE MODELING THE REST OF THE AIRCRAFT FLOW FIELD. THESE VERY DIFFERENT CODES PRESENT THE MOST DIFFICULT COUPLING PROBLEMS. THE SUCCESSFUL COMPLETION OF THE WORK WILL DEMONSTRATE THE FEASIBILITY OF THE ZONAL METHOD FOR ANALYZING COMPLEX FLOW FIELDS FOR COMPLICATED GEOMETRIES ASSOCIATED WITH POWERED-LIFT AIRCRAFT.