Drag Reduction of a Near-Sonic Airplane by Using Computational Fluid Dynamics

Aerodynamic shape optimization for an airplane cruising at a near sonic regime is discussed based on computational fluid dynamics. Japan Aerospace Exploration Agency's scaled experimental supersonic airplane model, NEXST 1, was employed as the baseline model of the optimization. NEXST 1 was accepted as a candidate for a near sonic airplane because of the existence of a "drag bucket" at a near sonic regime, as shown by the past research of the present authors. In the present optimization, the section airfoil shape and the planform shape were optimized independently of each other in the near sonic regime of Mach number 0.98. For the optimization, a genetic algorithm was used with unstructured mesh Enter simulations. The results of the optimizations showed considerable improvement in the lift to drag ratio in the near sonic regime. The optimization of the section airfoil shape and that of the planform shape yielded to the reduction of wave drag and induced drag, respectively. [PUBLICATION ABSTRACT]