Design and numerical simulation of a clamshell-shaped inlet cover for air-breathing hypersonic vehicles

Abstract

An efficient clamshell-shaped inlet cover configuration based on a shockwave interference methodology is proposed, which has the advantage of an autonomous opening using the aerodynamic force and moment. A preliminary design method for the inlet cover is introduced and used to produce cover models of two different lengths, with contributions similar to those of cowlings, rocket fairings, shrouds, or false ogives. The clamshell-shaped inlet cover features a practical design with a wide range of applications, including utilization in air-breathing hypersonic vehicles under specific constraints. In this investigation, aerodynamic numerical simulations were conducted to evaluate the extent to which the objectives and design principles are achieved for two typical ballistic separation states. The results show that both configurations can prevent an excessive accumulation of shockwaves in the nose cone area. In addition, the inlet cover generates negative lift, which results in the generation of an opening moment. The calculated heat flux at the leading edge of the clamshell-shaped inlet cover is approximately 13 MW/m2, which is within the limit of the composite material but slightly higher than that of the stagnation point of the nose cone.