Influence of the connection section on the aerodynamic performance of the tandem waverider in a wide-speed range

A novel design concept for hypersonic vehicles has been put forward to improve the aerodynamic performance of the hypersonic vehicle in a wide-speed range, namely the tandem wide-speed ranged hypersonic vehicle, and the influence of the connection section on the novel vehicleʼs aerodynamic performance has been performed numerically. Firstly, two waveriders at different Mach numbers (4Ma and 8Ma) have been designed based on the cone-derived waverider theory, and then a novel hypersonic vehicle has been constructed by combining the two vehicles in tandem. In the current study, the commercial software Fluent has been employed to numerically study the aerodynamic performances and flow field characteristics of the waveriders under different conditions. The obtained results show that the novel tandem waverider has good aerodynamic performance in a wide-speed range. With the increase of the connection sectionʼs length, the lift-to-drag ratio increases gradually, while its gradient decreases. When the freestream Mach number increases, the highest lift-to-drag ratio first increases then decreases. The thickening of the forebody and the broadening of the afterbody can both result in the increase of the lift-to-drag ratio and its corresponding best angle of attack. The appropriate configuration of the connection section is very important for the hypersonic vehicle which owns good aerodynamic performance in a wide-speed range. For instance, when the angle of attack is 3°, the lift-to-drag ratio of CL-7 is not lower than 3.36 in the wide-speed range, and its aerodynamic performance is better.