Design and assessment of short-in-length shape transition hypersonic inlet with circular throat

Abstract

This paper presents the design of an efficient, short-length shape transition inlet for hypersonic propulsion systems, operating at Mach 4 to 6. The inlet was shortened by approximately 24 % using a Busemann flow based on the median operating Mach number for streamline-tracing instead of the maximum operating Mach number. Additional upper circular arc of capture shape resulted in a compact compression surface that well preserves internal compression of the Busemann flow, and increased pressure rise by up to 31 % with higher total pressure recovery. The inlet was notched for maximum operating Mach number to minimize air spillage, and the range of operating Mach number and angle of attack was extended. Viscous effects were compensated by a proper truncation angle in order to maintain the exact circular throat shape for efficient manufacturing. The length-reduced inlet showed a wide operating range and high compression performance.