RESEARCH ON LOAD CHARACTERISTICS AND VARIATION LAWS OF UNDERWATER EXPLOSIONS COVERING THE ENTIRE DEPTH SCALE

Traditional theoretical models may deviate from the correct results and fail to meet accuracy requirements when calculating underwater explosion at large depth conditions due to exceeding their applicable range. In order to precisely study the load characteristics and variation laws of underwater explosion loads covering the entire depth scale, a theoretical model for calculating underwater explosion shock waves and bubble loads is established by combining the method for calculating shock wave loads in a projection coordinate system with a unified form of bubble dynamics equation proposed by Zhang et al.. The accuracy of the calculation results obtained from the model is well verified by the experimental and numerical results of underwater explosions at depths of hundreds of meters and kilometers previously published. At the same time, this article explores the variation of shock wave and bubble load and energy distribution with water depth in underwater explosions. It is found that with the increase of water depth H, the peak value of shock wave p_sm slightly increases, and the attenuation time of shock wave T_att gradually decreases. The negative pressure caused by pulsation is more obvious, and the proportion of shock wave energy propagating to the measure point and bubble energy decreases. The proportion of shock wave energy propagating to the measure point is related to the charge equivalent W, while the proportion of bubble energy is little affected by W. The acoustic radiation loss during the first collapse and expansion process of bubbles decreases. Fitted functions are given for describing the relations of p_sm, T_att, the pulsation period T and maximum radius R_m of underwater explosion bubbles between W and H. The calculation model of underwater explosion shock wave and bubble load used in this article can be applied to the calculation of underwater explosion load in the entire sea, and the trend of load variation and its fitting formula obtained can provide reference for deepwater explosion and structural anti explosion design.