Improvement and verification of low-speed aerodynamic characteristics of a supersonic civil transport aircraft

Abstract

For supersonic civil transport aircraft, the low-speed aerodynamic characteristics form an important factor in its operational capabilities and in its economic viability. Low drag is a prerequisite to meet the present and future noise and emissions requirements. The application of concepts for leading-edge devices aiming at an improvement of low-speed aerodynamic efficiency is investigated. From computational analysis of a series of leading-edge flap designs, the two most promising devices are selected for experimental verification, viz. a doublehinge leading-edge flap and a deep-hinge leading edge flap design. In the course of comparing experimental and computational results, discrepancies are observed that are satisfactorily dealt with by adding the wind tunnel struts and the strut-wing connections in the computational analysis. Reynolds number extrapolations from wind tunnel scale to full-scale are obtained using computional fluid dynamics (CFD). It is concluded that the design approach based on CFD has significantly contributed to the success of configuration development, meeting the target efficiency improvement. Furthermore, the influences of geometrical details that differ in the design phase and the validation phase have been assessed.