Aerodynamic Design Optimization of A Cruise-Slotted Transonic Truss-Braced Wing for Turbulent Flow

This paper investigates the aerodynamic design and performance of a cruise-slotted transonic truss-braced wing (TTBW) aircraft configuration through the application of aerodynamic shape optimization based on the Reynolds-averaged Navier-Stokes equations. The TTBW and cruise-slotted wing are two advanced air transport technologies that can significantly improve aerodynamic efficiency, primarily through a reduction in induced drag, and the mitigation of shock formation and boundary layer separation, respectively. However, it remains to be seen whether these technologies can be combined while retaining the individual benefits. To address this question, aerodynamic shape optimization is applied to the wing and strut of a wing–strut–fuselage geometry of the cruise-slotted TTBW configuration, as well as a non-slotted TTBW serving as a reference aircraft. Results indicate that aerodynamic shape optimization is successful in achieving an aerodynamically efficient cruise-slotted TTBW design for fully turbulent flow, with similar features to those of the optimized non-slotted TTBW. With regard to aerodynamic performance, the optimized cruise-slotted TTBW experiences more drag at Mach 0.800 than the non-slotted variant, but has the advantage of a more gradual drag rise as the operating Mach number is increased. This was found to be the case even when optimizing the two configurations for higher design Mach numbers. However, the low wave drag of both sets of optimized designs mitigates the airfoil technology factor advantage of the cruise-slotted wing, resulting in lower maximum aerodynamic range efficiency.