Optimum design of high speed prop-rotors using a multidisciplinary approach

The design of advanced high speed prop-rotor aircraft is addressed using a formal multidisciplinary optimization procedure. The optimization problem is formulated with aerodynamic performance, dynamics, aeroelastic stability and structural design requirements. Both high speed cruise and hover flight conditions are addressed. The analysis is performed at a cruise speed of 400 knots. The efficiency in cruise is maximized without deteriorating hover performance. Constraints are imposed on fundamental frequency, blade weight, thrust in hover, total power required and aeroelastic stability in cruise. A wide selection of structural and aerodynamic design varaibles are used. The optimization is performed using a nonlinear programming procedure and an approximate analysis technique. The procedure yields significant improvements in the overall rotor performance.