Propagation characteristics of blast wave in diminished ambient temperature and pressure environments

The effects of different diminished ambient pressure, temperature and altitude from sea level on blast wave parameters (overpressure, impulse and wave front trajectory) were investigated by employing the dimensional analysis theory and the AUTODYN software. Meanwhile, the relationship equations between the blast wave parameters with the diminished pressure and temperature were established, which were verified by numerical simulations and experimental data. Results indicate that the equations can evaluate the blast wave parameters at diminished temperature and pressure effectively. It is noted that the blast wave overpressure and far-field (scaled distance Z＞0.2 m/kg1/3) impulse decrease, but the propagation velocity increases, as the ambient pressure decreases. The blast wave impulse increases, and the propagation velocity decreases, but has little effect on the overpressure, as the ambient temperature decreases. It is shown that when the altitude increases by 1000 m in the range from 0 to 9000 m above sea level, the overpressure and far-field impulse of the blast wave decrease in average by about 3.9% and 3.2%. In addition, the blast wave propagation velocity in the near field increases, but it in the farfield decreases with the altitude increase. The influences of the diminished pressure on the blast wave overpressure and impulse are greater than those of the diminished temperature at high altitudes. The blast wave propagation velocity depends on the diminished pressure in the near field, but on the diminished temperature in the far field. © 2023 Explosion and Shock Waves. All rights reserved.