Numerical Study on Shock-Induced Combustion of a Blunt Projectile via an Adaptive Mesh Program

Shock-induced combustion of a blunt projectile is a basic problem in detonation research. Numerical simulations were conducted to study the shock-induced combustion phenomenon of a stoichiometric H2/Air mixture at the flow Mach numbers of 4.79 and 6.46. The block-structured adaptive mesh refinement program AMROC based on the finite volume method was adopted to solve the axisymmetric Euler equations with chemical reaction source terms, and the influence of some important factors such as the form of the MUSCL reconstruction, the slope limiter types, and the chemical reaction mechanisms were investigated. The results show that, based on the mesh adaption flag parameters, the program can realize adaptive mesh refinement efficiently. The comparisons with experimental results show that the accuracy of the unsteady shock-induced combustion simulation depends not only on the chemical reaction mechanism, but also on the form of the limiter. Adopting two different forms of the MUSCL reconstruction format acquires almost the same oscillating frequencies, which is 1.17% and 0.97% different from the result obtained in the experiment, respectively. Numerical study is conducted for comparing the classic Jachimowski mechanism with several newly developed pressure-dependent hydrogen/oxygen reaction mechanisms. It is shown that, in the unsteady shock-induced combustion case at Ma=4.79, the classic Jachimowski mechanism is still the most suitable mechanism to obtain the closest oscillating frequency to the experimental result. While in the steady shock-induced combustion case at Ma=6.46, all of the given mechanisms can give results that are in good agreements with the experiment. © 2021, Editorial Department of Journal of Propulsion Technology. All right reserved.