低温和低压环境下炸药爆炸冲击波的传播特性

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

针对高海拔或高空的低温、低压环境对炸药爆炸冲击波传播的影响,利用量纲分析理论和AUTODYN有限元软件,研究了低温、低压及海拔高度对炸药爆炸冲击波参量(峰值超压、比冲量和波阵面运动轨迹)的影响规律,建立了相应的计算公式,并通过数值模拟和实验数据进行了对比验证。结果表明,该计算公式可以有效预测低温和低压环境下炸药爆炸冲击波参量。环境压力降低,爆炸冲击波峰值超压和爆炸远场(比例距离Z>0.2 m/kg^(1/3))比冲量减小,冲击波传播速度增大。环境温度降低,冲击波比冲量增大,传播速度降低,峰值超压影响不大。海拔高度在0~9000 m范围内,每升高1000 m冲击波峰值超压和爆炸远场比冲量分别平均降低约3.9%和3.2%。海拔升高,爆炸近场冲击波传播速度升高,爆炸远场冲击波传播速度则降低。高海拔环境下低压对冲击波峰值超压和比冲量的影响大于低温,爆炸近场冲击波传播速度取决于低压的影响,爆炸远场冲击波传播速度取决于低温的影响。

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/kg^(1/3))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.