Hypersonic Inlet for a Laser Powered Propulsion System

Abstract

Abstract. Propulsion within the lightcraft concept is produced via laser induced detonation of an incoming hypersonic air stream. This process requires suitable engine configurations that offer good performance over all flight speeds and angles of attack to ensure the required thrust is maintained. Stream traced hypersonic inlets have demonstrated the required performance in conventional hydrocarbon fuelled scramjet engines, and has been applied to the laser powered lightcraft vehicle. This paper will outline the current methodology employed in the inlet design, with a particular focus on the performance of the lightcraft inlet at angles of attack. Fully threedimensional turbulent computational fluid dynamics simulations have been performed on a variety of inlet configurations. The performance of the lightcraft inlets have been evaluated at differing angles of attack. An idealized laser detonation simulation has also been performed to validate that the lightcraft inlet does not unstart during the laser powered propulsion cycle.

Supersonic laser propulsion

“…To obtain optimal supersonic mode of the LIGHT-CRAFT operation, the condition of precise pressure recovery of gas flow in the slit inlet in dependence of the incoming flow Mach number is determined [22]. The forebody surface is shaped in such a way that a bow shock wave arising in supersonic flow directs incoming flow into the slit nozzle without additional pressure losses and shocks (Fig.…”

“…But the experiments carried out by the authors demonstrated essential instability of thrust production in this case. Analysis of the experiments shows that the technique of thrust production imposes mutual constraints on laser characteristics as a function of flow parameters [16].…”