Quasi-One-Dimensional Thermodynamic Analysis of Radially Expanding Laser-Supported Detonations

Repetitively pulsed (RP) laser propulsion is regarded as an alternative to chemical rockets for space launches, potentially offering remarkable cost reductions. Understanding the physics of laser-supported detonation (LSD) is important for designing a high-performance propulsion system. Experimentally observed LSD propagation velocities are reportedly lower than the Chapman–Jouguet (C-J) velocity; hence, a previous study that examined two-dimensional expansion behind the LSD to perform Hugoniot analysis using computational fluid dynamics (CFD) simulation resulted in strong detonation solution. In the present study, the effects of varying the relationship between heating and propagation velocity are investigated using CFD simulations. The findings indicate that a weak detonation solution was obtained with more realistic input of heating rate distribution and the pressure behind the LSD wave was lower than that in C-J detonation by a factor of three. The input LSD propagation velocity was changed by ±30% in the CFD simulation to examine the case of faster propagation in helium and slower propagation in argon and even so, a weak detonation mode was maintained. However, the input relaxation distance from the electron temperature to heavy particle temperature that is shorter in a light gas such as helium can produce a solution of C-J or strong detonation.