Numerical Analysis of High-Speed Flow Around a Double-Delta Wing

In recent years, supersonic passenger and fighter aircrafts have been receiving an increased interest. These aircrafts usually require thin delta wings with a large leading-edge recession angle. This is because delta wings have an advantage in reducing pressure drag, and that can be obtained without structural difficulties and their small frontal projected area. The flow behavior of a delta wing with a small leading-edge recession angle in low-speed flow has been extensively studied, however, the flow behavior in transonic flow regime has not been well elucidated, so far. In this study, the flow behavior around a double delta wing that was modelled after the Grumman X-47B was investigated by using the computational fluid dynamics (CFD) analysis. 4 (four) different leading-edge shapes, namely ‘sharp’, ‘round’, ‘triangle’ and ‘round nosed triangle’ were used to investigate the influence of leading-edge shapes on the flow features. Moreover, the mainstream flow velocity was varied from subsonic to transonic to investigate the effect on wing characteristics. From the results, it was found that the round nosed triangle leading-edge shape of the delta wing delays the formation of vortices and the stall, and moreover, it obtained the best lift-to-drag ratio in a wide flow regime.