Analysis of Square Wave Characteristic Based on Viscous Flow CFD
Abstract When two waves in different directions meet due to different weather patterns, a cross wave pattern will be generated, which will finally result in the spread of square waves on the sea surface. The emergence of square waves will threaten the navigation performance of a ship and may lead to capsizing of a ship in severe cases. In this paper, the numerical square wave tank is developed by using the in-house CFD software HUST-Ship. In the process of simulation, by means of solving the unsteady RANS equation of incompressible fluid, the analytical solution of the corresponding regular wave is generated at the inlet boundary, and the free surface is captured by level-set method. Square wave is generated by superimposing two vertical regular waves with the same wave length, wave height and phase. Through analyzing the CFD model of square wave, the uncertainty analysis of wave height and length are performed. The verification and validation procedures of grid and time-step are performed to ensure the credibility of simulation results. Moreover, a detecting point is set at the origin to get the time history curve of the wave height. The linear solution and second-order Stokes solution of waves are used to fit the wave height time-history curve respectively.