Theoretical analysis and validation of the detonation wave interaction based on an overdriven detonation

The oblique collision and reflection of a detonation wave can lead to extremely high pressure and considerable dynamic load mixing in the resulting product, which has been a focus of research in detonation and defense applications. In this paper, the relationships among wave velocity, mass velocity, pressure, and the specific volume of detonation products (DPs) under overdriven detonation (ODD) conditions are analyzed. Additionally, the equations of state (EOS) of the ODD are calibrated by using real-coded genetic algorithms combined with experimental Hugoniot strong detonation data, and the effects of different DPs on pressure accuracy are assessed. Accordingly, a dynamic evolution model of detonation wave interactions in a collision zone is established, and theoretical calculations of regular and Mach reflections occurring after the interactions of typical condensed explosive [such as PBX9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/F)] detonation waves are carried out. The results show that the overpressure Hugoniot data and the isentropic expansion line can be better fitted by using the JWL (Jones-Wilkins-Lee) + γ equation than other EOSs, and the deviation of the calculated pressure and the height of the Mach stem from the experimental value is within 5%. Additionally, a formula is derived for the slow-variable function k(ξ) by combining the improved Whitham method and the JWL + γ EOS, and a propagation law is obtained for the detonation wave interaction.