Lift Augmentation at Subsonic Speeds by Lateral Jets for a Hypersonic Aircraft

Abstract

This paper presents a numerical investigation on the lift augmentation at subsonic speeds by using lateral jets for a hypersonic aircraft equipped with a waverider-type lifting body, which consists of three main parts. The jet slots were arranged along the side edges of the lifting body to study the effect of lateral blowing on the lift augmentation at a freestream Mach number of 0.3. The numerical results based on solving the Reynolds-averaged Navier–Stokes equation indicate that a well-designed lateral blowing can produce a significant lift rise. Then, further work was carried out to investigate the effects of jet parameters, including the jet location, the blowing strength and the blowing direction on lift augmentation, and to provide insights into the associated flow physics. It was found that blowing on the middle and rear parts of the lifting body achieves the maximum lift augmentation among the chosen configurations. Additionally, it was confirmed that the lift augmentation increases as the jet momentum increases, and blowing in the direction of θjet = −45°, which means the jet blows slightly towards the lower surface of the lifting body, produces a larger lift rise than other directions. The lift augmentation can be explained by the fact that a well-designed lateral blowing can amplify the effectiveness of the vortices shedding from the side edges of the lifting body, resulting in an increase in the vortex lift.