Detonation wave propagation in micro-scale groove charges

The detonation wave propagation characteristics in micro-scale groove charges are very important for optimizing the structure of the Micro-Electro-Mechanics System explosive train and improving its detonation reliability. Focusing on the problem of detonation wave propagation of micro-scale groove charges under strong confinement, the effects of charge density, groove size and confinement are considered. A theoretical model of curved detonation wave propagation in a micro-scale groove charge under a strong confinement was established by means of equivalent mass correction. The mathematical expression for the detonation velocity was derived and a numerical calculation method of detonation velocity and shock front shape was given using MATLAB software. An experiment was designed to test the detonation velocities for micro-scale groove charges with a booster explosive. The results closely agreed with the calculations, validating the propagation model of curved detonation waves. The results show that the smaller the groove size, the bigger the detonation velocity loss and the curvature of shock front in the central axis. When the charge size was 0.6×0.6mm, the detonation velocity loss was 11.49%. The detonation velocity and maximum streamline deflection angle increase with increasing charge density and size. The increase of streamline deflection angle reduces the detonation velocity of the explosive. However, the streamline deflection angle changes by only a small amount in the micro-scale with an effect on the detonation velocity of less than 1%. The detonation velocity has a strong correlation with charge size and density. This paper contains theoretical guidance for the design and performance optimization of charge structures in the MEMS explosive train.