Session: 08-06-01 non-presentations

Paper Number: 127786

127786 - New Progress of Vapor-Liquid Phase Change Model in Cavitation Prediction of Underwater Explosion 

Near-free surface underwater explosion cavitation has the remarkable characteristics of wide distribution area, fast evolution and multiphase flow coupling, and its motion law is very complex, so it is very difficult to study. For this reason, a multiphase compressible fluid model based on thermodynamic phase transition is introduced, which is composed of 4-equation and phase transition model. The homogeneous hyperbolic equation is analyzed by MUSCL-Hancock reconstruction scheme and HLLC approximate Riemann solver, and the phase transition equation is solved by Newton-Raphson iterative method. Firstly, the cavitation process caused by small charge explosion near the water surface is simulated by using a two-dimensional axisymmetric model, and it is found that the cavitation evolution process will develop from the initial single-connected domain to multi-connected domain, and the typical vortex ring phenomenon will appear. When the volume fraction of steam in the fluid in the numerical simulation is more than 0.5 ‰ as the criterion of the cavitation domain, the calculated cavitation domain shape and its motion process are in good agreement with the experimental results, which shows that the calculation model has a certain accuracy. At the same time, it is found that the distribution of pressure and steam volume fraction in the cavitation domain is obviously non-uniform, which is not maintained at a constant value. On this basis, the motion characteristics of near-free surface cavitation under different detonation depth and charge are studied, and the partial motion law of cavitation is obtained. It is found that under the condition of the same explosion depth, with the gradual increase of the charge, the movement period increases rapidly at the beginning, and then slows down gradually, while the maximum volume of the cavitation domain increases linearly with the increase of the charge. The above research results can provide important support for the cavitation motion characteristics and the impact damage to the structure in the process of near-surface explosion.

Presenting Author: Jun Yu China Ship Scientific Research Center

Presenting Author Biography: Jun Yu, born in 1984, holds a master's degree from University of Science and Technology of China and is an senior engineer engaged in research on underwater explosions and CFD.

Authors:

Jun Yu China Ship Scientific Research Center
Tongtong Guo China Ship Scientific Research Center
Jiping Chen China Ship Scientific Research Center
Xianpi Zhang China Ship Scientific Research Center
Chao Shen China Ship Scientific Research Center
Jing Zhang China Ship Scientific Research Center