Investigation on the cavitation effect of underwater shock near different boundaries

• Published in: China ocean engineering Vol. 31; no. 4; pp. 396 - 407
• Main Authors: Xiao, Wei, Wei, Hai-peng, Feng, Liang
• Format: Journal Article
• Language: English
• Published: Nanjing Chinese Ocean Engineering Society 01.08.2017; Springer Nature B.V; College of Engineering, Ocean University of China, Qingdao 266100, China%Beijing Institute of Astronautical System Engineering, Beijing 100076, China
• Subjects: Approximation; Boundaries; Cavitation; Coastal Sciences; Computer simulation; Distortion; Duration; Dynamic response; Engineering; Equations of state; Finite element method; Fluid- and Aerodynamics; Marine & Freshwater Sciences; Mathematical models; Numerical and Computational Physics; Oceanography; Offshore Engineering; Peak pressure; Shock waves; Simulation; Spectral element method; Spherical shells; Superposition (mathematics); Underwater; Underwater explosions; Vapor pressure; Vapour pressure; Water depth; Wave propagation; boundary; fluid structure interaction; spectral element; underwater explosion; cavitation
• DOI: 10.1007/s13344-017-0046-x
• ISSN: 0890-5487

When the shock wave of underwater explosion propagates to the surfaces of different boundaries, it gets reflected. Then, a negative pressure area is formed by the superposition of the incident wave and reflected wave. Cavitation occurs when the value of the negative pressure falls below the vapor pressure of water. An improved numerical model based on the spectral element method is applied to investigate the cavitation effect of underwater shock near different boundaries, mainly including the feature of cavitation effect near different boundaries and the influence of different parameters on cavitation effect. In the implementation of the improved numerical model, the bilinear equation of state is used to deal with the fluid field subjected to cavitation, and the field separation technique is employed to avoid the distortion of incident wave propagating through the mesh and the second-order doubly asymptotic approximation is applied to simulate the non-reflecting boundary. The main results are as follows. As the peak pressure and decay constant of shock wave increases, the range of cavitation domain increases, and the duration of cavitation increases. As the depth of water increases, the influence of cavitation on the dynamic response of spherical shell decreases.