Load Characteristics of Shock Wave under Condition of Multiple Underwater Explosion (UNDEX)

According to the actual combat background of underwater multiple initiation, the numerical simulation of shock wave load characteristics under the condition of two-point simultaneous initiation is carried out. Based on the self-developed multiphase compressible fluid calculation program, a high precision numerical scheme is used to discretize the fluid control equation. Firstly, the results of free-field underwater explosion calculated by the numerical model are compared with the theoretical results, and the accuracy and reliability of the numerical model are preliminarily verified. And then this numerical model is used to calculate the underwater two-point initiation condition under typical working conditions. The results show that the pressure on the symmetrical plane of the two explosion sources increases by 12% to 16% compared with the peak pressure after the linear superposition of the single explosion source. There is a bimodal phenomenon in the pressure between the vertical sections of the two explosion sources. For the pressure at the measuring point outside the two vertical sections, there is also a double-peak phenomenon, the first peak pressure is equal to the peak value of the linear superposition of the single explosion source, and the second peak pressure is much lower than the peak value of the linear superposition of the single explosion source. The peak pressure can be reduced by as much as 30%. The research results of this paper can provide reference for underwater weapon protection design and threat assessment.