Pulsed Laser-Generated Impulse on a Surface in Supersonic Flow

Abstract

I T is now well known that pulsed CO 2 laser radiation can generate high pressures over a surface through formation of laser-supported detonation (LSD) waves at fluxes greater than 10 7 W/cm 2 (Refs. 1-3). It is also possible for hot, dense plasmas to be produced in the strong laser-supported combustion (LSC) wave regime at fluxes between 10 6 -10 7 W/cm 2 (Refs. 4 and 5). The impulse generated at the surface by these phenomena are reasonably well understood. 6 Previous analytical and experimental work has dealt with a static environment. The phenomenology should be different with a supersonic crossflow over the surface. This work examines the behavior of the laser/surface/supersonic flow interaction and presents impulse data from aluminum targets.

Modeling of Momentum Transfer to a Surface by Laser-Supported Absorption Waves

“…However, there is evidence to suggest that the pressure relaxation process occurs on a time scale commensurate with the sound speed being of approximately this value. 10 The evaluation of r z for the LSD wave can be made in terms of the method of characteristics. The sound speed in the region behind the detonation wave has the form shown in Fig.…”

<title>Laser-produced plasma in high-speed flows</title>

“…In the previous study by Woodroffe et al, the behavior of laser / surface / supersonic flow interactions were examined (Ref. 7). Laser beam was focused onto a bottom aluminum surface in a wind tunnel that operates at a 2.8 Mach number.…”