Experimental demonstration of a new concept of drag reduction and thermal protection for hypersonic vehicles

Abstract

A new idea of drag reduction and thermal protection for hypersonic vehicles is proposed based on the combination of a physical spike and lateral jets for shockreconstruction. The spike recasts the bow shock in front of a blunt body into a conical shock, and the lateral jets work to protect the spike tip from overheating and to push the conical shock away from the blunt body when a pitching angle exists during flight. Experiments are conducted in a hypersonic wind tunnel at a nominal Mach number of 6. It is demonstrated that the shock/shock interaction on the blunt body is avoided due to injection and the peak pressure at the reattachment point is reduced by 70% under a 4 • attack angle.

Aerothermodynamics of Spiked Bodies: Part I

“…Lateral jets of hydrogen were injected from orifices in the side face of the aerodisk. A similar (but briefer) investigation was conducted by Jiang et al[31]. A hemisphere cylindrical model equipped with a blunt tipped spike (…”

“…A lateral jet of air was applied at the shoulder of the spike's rounded tip. It was believed [31] that the use of jet broadens the range of incidence angles within which the spike will be effective in reducing the drag (such as that discussed by Huebner [6]).…”

“…In addition, the spike becomes effective only if the forebody is blunt enough to generate a bow shock wave ahead of it [30]. Moreover, structural and rigidity considerations should be taken into account in cases of very long spikes and measures should be taken to reduce the intensive heating loads at the spike tip [31]. Whether the attachment of the spike at the tip of the blunt forebody nose will affect the function of any seeker devices should also be considered [32].…”

A survey of drag and heat reduction in supersonic flows by a counterflowing jet and its combinations

“…In Fig.11, M stands for the freestream Mach number. The lateral jets are used to push the conical leading shock wave away from the blunt body (Jiang et al, 2009), as shown in Fig. 12 (Liu and Jiang, 2013).…”

An Expedient for Alleviating Aerodynamic Heating and Drag on Capsule Forward Heat Shield

“…Other idea was studied by Jiang el al. 5,6 . They paid attention to the fact that the spike can reduce aerodynamic heating or pressure on entire blunt body only when angle of attack is zero.…”