Prediction Method of Triple Point Trajectory in Shock Wave Flow Field of Near-earth Air Blast

To study the rule of the triple point (TP) trajectory in the shock wave flow field of the near-earth air blast, the TP path prediction model was obtained by the constructed TP geometric constraints from the mirror image method, combining with the LAMB model and the polynomial fitting method. First, the TP geometric constraint based on the explosion height is constructed as the starting point (SP) by the mirror image method. The starting angle of the prediction model is calculated by multiplying the incident angle and the scaling factor. Second, the trajectory prediction equation is constructed according to the geometrical relationship between the TP trajectory and the SP. Then, unknown parameters of the model are determined by the TP data at different explosion height. Finally, based on the numerical simulation results, the known TP data, and the real blasting data, the model verification is evaluated and compared with the existing methods. The results show that the prediction model results of triple point are consistent with the real blasting data. When the scaling explosion height is from 0.35 to 1.42 and the horizontal scaling distance is less than 10, the TP trajectory output by the prediction model is more accurate and reliable. © 2021, Editorial Board of Journal of Explosives & Propellants. All right reserved.