Numerical investigation of interface capturing method by the Rayleigh-Taylor instability, dambreak and solitary wave problems

Free surface simulation always plays an important role among the problems in ship and ocean engineering. In the research described herein, an interface capturing method, combined with the level set (LS) and volume of fluid (VOF) method (CLSVOF), was developed and verified detailedly on the basis of the Rayleigh-Taylor instability (RTI), dambreak and solitary wave problems numerically in two-dimensional (2D) situation. According to CLSVOF approach, the LS function but not the VOF function can estimate the interface normal vector in the reconstruction procedure of interface. The numerical solver was first verified by solving the single-mode RTI. After that, the shape of the interface, the evolution process of vortices and the relationship between penetration depth and time were obtained. Simultaneously, this article separately discussed the effects of surface tension, density ratio and viscosity ratio on the RTI. Next, for the multi-mode RTI, the complicate interface evolution process was finely simulated to verify the mass conservation property during simulation. Eventually, this paper shows dambreak and solitary wave problems to demonstrate that CLSVOF solver is capable of handling a large density difference situation, as well as wave profile evolution in ocean engineering application.