Study on cavitation induced by near-field underwater explosion on conical wall

Objectives To establish a high-precision numerical method for predicting cavitation loads induced by near-field underwater explosions on complex rigid walls, and explore the effects of conical wall geometry and explosion parameters on cavitation evolution and load distribution. Methods An isentropic cavitation flow model was adopted to construct the RKDG-GFM-IsenCav computational framework. The cavitation boundary and collapse time history of a one-dimensional benchmark of water-backed Taylor plate were reproduced. The wall pressure acquired from a two-dimensional case was compared with experimental measurements, and the peak errors of the two monitoring points were 2.1% and 2.43%, respectively. The two cases together verified the prediction accuracy of the model for the full cavitation process and shock wave response. The validated model was applied to conical walls to analyze the influences of wall length, cone angle, explosion distance and explosion depth on cavitation evolution and loads. Results Wall length and explosion distance act as dominant factors. Reduced wall length weakens flow field constraints, limiting cavitation development and advancing the response onset. Larger explosion distance delays cavitation inception, lowers cavitation intensity, and shifts the cavitation region to the far field. The cone angle exerts a minor effect, with the variation amplitudes of cavitation area and collapse load both below 10%. Increased explosion depth suppresses cavitation evolution; under the 1000 m working condition, the secondary collapse pressure peak can reach 75% of the initial shock wave pressure. Conclusions The differentiated regulation mechanism of conical wall geometry and explosion parameters on cavitation loads is clarified. Wall length and explosion distance are the dominant parameters, the cone angle has limited impact, and explosion depth significantly strengthens the secondary shock response.