Optimization of transition maneuvers through aerodynamic vectoring

Abstract

This paper discusses the optimization of transition maneuvers between hover and cruise for small aircraft using a novel aerodynamic vectoring feature, which is achieved by allowing the wing to have variable incidence angle with respect to the fuselage. Compared to the fixed-wing aircraft case, the angle of incidence of the wing provides an additional independent control variable in the optimization problem formulation. The objective of the study is to achieve a transition scheme with minimal variation in altitude and reasonable thrust-to-weight ratio under specified transition time. The aerodynamics of the aircraft in pre- and post-stall regimes are obtained through wind-tunnel tests. The unsteady aerodynamic effects are incorporated in aerodynamic model to cater for rapid changes in the aircraft motion, which is modeled as three degree of freedom longitudinal dynamics. A nonlinear constrained optimization scheme based on Sequential Quadratic Programming (SQP) is used to generate the optimal maneuver motions. The results are discussed in light of their comparison with the fixed-wing case.