Optimization of Variable-Camber Continuous Trailing-Edge Flap Configuration for Drag Reduction

The variable-camber continuous trailing-edge flap is a novel control surface technology designed to serve as an aeroelastic wing shaping control device. Capable of minimizing drag throughout an aircraft flight envelope, use of the variable-camber continuous trailing-edge flap technology is examined on a flexible-wing transport aircraft configuration known as the NASA generic transport model. Drag reduction studies at various flight conditions are conducted in order to examine the performance of different flap configurations with selected camber deflection profiles. Rapid optimization of the design space is achieved by using aerodynamic-structural modeling based on a vortex lattice method coupled with transonic small disturbance and integral boundary-layer solutions. The begin cruise optimization results show that a parabolic flap deflection profile configuration with three-cambered-segments achieves the largest drag reduction of 8.4% as compared to a clean wing configuration. The configuration is used to run additional optimizations measuring performance benefits at different flight conditions including 20% fuel end cruise, a +/- 30% design lift coefficient, and a Mach overspeed condition. The optimization framework and initial results produce insights that can be used to refine the optimization of variable-camber continuous trailing-edge flap configurations with higher-fidelity aerodynamic tools.