Numerical Simulation and Uncertainty Analysis of Wave-Co-Current Interaction with Irregular Waves

Uniform current effects on the characteristic of irregular waves along with its uncertainty are presented considering wave-current interaction in the actual ocean environment. First, relative tests of interaction of irregular wave and uniform current are conducted in the circulating water channel at Shanghai Jiao Tong University. Then, the wave elevations are measured to validate the numerical results obtained from the numerical simulation of wave-current interaction based on Reynolds-Averaged Navier-Stokes (RANS) equations. Finally, significant wave height and average period of irregular wave are selected to conduct the uncertainty analysis including both grid-convergence and time-step-size convergence studies. The results show that wave height probability distribution agrees well with Rayleigh distribution in the co-current and no-current cases. The spectral peak of irregular wave moves to the low frequency in the co-current conditions. Besides, significant wave height of irregular wave is more sensitive to grid size, while the average period is more affected by time step size. Moreover, uniform co-current can reduce the degree of dependence of significant wave height on time step size, while the influence on the average period is on the contrary.