PERFORMANCE OPTIMIZATION FOR ROTORS IN HOVER AND AXIAL FLIGHT

THE ROTORCRAFT COMMUNITY HAS A CONTINUING NEED FOR IMPROVED DESIGN TECHNIQUES FOR HOVER AND AXIAL FLIGHT. SUCH TECHNIQUES CAN BE EMPLOYED TO BEST ADVANTAGE IF THEY ARE COUPLED WITH NUMERICAL OPTIMIZATION METHODS. THIS COUPLING WOULD MINIMIZE TRIAL AND ERROR COMPUTATIONS WHEN SEARCHING FOR CONFIGURATIONS TO MEET PARTICULAR DESIGN SPECIFICATIONS. A NEW, HIGHLY ADVANCED HOVER PERFORMANCE ANALYSIS RECENTLY DEVELOPED AT CONTINUUM DYNAMICS, INC. IS UNIQUELY SUITED TO SERVE AS A FOUNDATION FOR THE DEVELOPMENTOF AN OPTIMIZATION ANALYSIS. THIS NEW ANALYSIS USES AN EFFICIENT WAKE RELAXATION TECHNIQUE IN CONJUNCTION WITH A LIFTING SURFACE LOADS ROUTINE TO PRODUCE ACCURATE FREE WAKE PREDICTIONS OF HOVER PERFORMANCE. AS A BY-PRODUCT OF THE SOLUTION METHOD, ARRAYS OF INFLUENCE COEFFICIENTS RELATING THE ROTOR LOADS AND WAKE GEOMETRY TO THE DOWNWASH ARE GENERATED. THESE ARRAYS, WHICH CAN BE EXPANDED TO INCLUDE THE EFFECTS OF PERTURBATIONS IN GEOMETRIC QUANTITIESSUCH AS BLADE TWIST, SWEEP OR TAPER, ARE WELL SUITED FOR USE IN THE DEVELOPMENT OF AN OPTIMIZATION SCHEME. THE EXTENSION OF THE HOVER ANALYSIS TO INCLUDE A DESIGN OPTIMIZATION CAPABILITY WOULD PRODUCE A HIGHLY ACCURATE AND EFFICIENT TOOL FOR THE DESIGN OF ADVANCED ROTORCRAFT BLADES.