Study on Pressure Characteristics and Its Evolution Law at the Ellipsoidal End Cover Pole of Cylindrical Explosion Containment Vessels

To explore the postposition of the maximum pressure at the pole of the ellipsoidal end cover of cylindrical explosion containment vessels and to reveal the mechanism of the load evolution, the experimental method was used to measure the pressure curve at the pole under different charges, and the numerical simulation method was used to analyze the evolution law of the explosion flow field within the end cover. The results show that the end cover pole was subjected to three types of pressure: the primary explosion wave, the secondary shock wave and the convergence wave. In addition, the pressure peaks increased in sequence. The evolution of the flow field in the end cover was affected by the amount of charge and the aspect ratio of the vessel. When the scaled distance due to a small charge increased, or when the aspect ratio of the vessel was reduced, the time interval between the convergence wave and the secondary shock wave at the end cover pole decreased gradually. When the scaled distance increased to 4.05 m·kg−1/3, the convergence wave at the pole superimposed on the secondary shock wave. As the aspect ratio of the vessel ranged from 1.75 to 2.50, the time interval between the two peaks was about 150 μs. However, if the aspect ratio was less than 1.40, the convergence wave and the secondary shock wave were fused through complex interaction.