Research on Calculation Method of Bubble Energy at Certain Distance Subjected to Underwater Explosion

Bubble load is an important explosive load in the middle and far field of underwater explosions. The calculation of bubble energy has not been thoroughly investigated, making it difficult to predict bubble energy accurately. In recent research, the neglect of bubble energy at certain distance leads to inaccurate calculations of total bubble energy. This study proposes a novel method for calculating bubble energy at certain distance, which is developed through theoretical analysis and experimental data fitting. First, calculation models for bubble energy at certain distance were proposed, in conjunction with research on bubble propagation characteristics. Second, the floating-up distance and the peak bubble pulsation pressure were derived from experimental data, subsequently determining the bubble energy. Third, the effects of suspender depth, charge quantity, and scaled distance on the bubble pulsation pressure peak and bubble energy at certain distance were discussed. The results indicate that the bubble pulsation pressure peak increases as the floating-up distance decreases; suspender depth and charge quantity have a minor impact on the pressure peak; and bubble energy increases as suspender depth and floating-up distance decrease and charge quantity increases. Moreover, it was found bubble energy is closely related to the bubble floating-up distance and pressure peak. The methods proposed in this paper provide a valuable approach for precisely calculating bubble energy at certain distance.