Experimental and numerical analysis of near-field detonation products and shock wave characteristics for cylindrical charge

Predictions of extreme near-field blast wave for cylindrical charge is crucial for designing sympathetic detonation protection structures, yet the quantitative analysis of detonation products and shock wave field are still insufficient. The present work conducted experiments and numerical simulations of near-field explosion for kilogram scale cylindrical charge, and investigated the propagation and spatial distribution characteristics of incident and reflected blast waves. The results show that near-field reflected overpressure exhibits multi-peak structures, which are primarily governed by reflections of detonation products and shock wave. The reflected peak overpressure dominated by detonation products shows higher sensitivity to scaled distance. Meanwhile, the Rayleigh-Taylor instability (RTI) effect induces the evolutions of detonation products and shock wave interface from smooth to random microjets, increasing dispersion of secondary reflected peak overpressure. In free-field explosion, the incident peak overpressure exhibits a dual-peak structure, governed by the shock wave front and detonation products flowing past the gauge points. The incident peak overpressure dominated by detonation products is sensitive to orientations due to the charge structures. As the aspect ratio of charge increases from 0.6 to 8, the dominant radial azimuth angle region expands from 60°–90° to 30°–90°. An empirical model was developed to predict the spatial distributions of incident peak loads at arbitrary orientations for cylindrical charge with 0.6 ≤ L/D ≤ 8.0 and 0.06 m·kg^−1/3 < Z < 1 m·kg^−1/3, and the average deviation is less than 30%. This study elucidates the coupled characteristics of near-field detonation products and shock wave for cylindrical charge, providing significant values for accurate assessments of near-field explosion.