Abstract:When waves incident on a vertical wall at angles smaller than a specific critical angle,the phenomenon of Mach reflection occurs.In addition to the incident and reflected waves,a Stem wave propagating along the wall is generated near the vertical wall.During its propagation,the wave energy of the Stem wave increases rapidly,posing a significant threat to the stability of marine structures.Currently,research on the evolution characteristics of Stem wave patterns under regular wave conditions is relatively limited,particularly in terms of systematic quantitative analysis of the critical incident angle,wave height,and wave width.On the basis of the Boussinesq model,the critical incident angle of Stem wave formation and the effects of incident wave height and angle on the wave height and width of Stem waves are systematically investigated through numerical simulations.The results show that the critical incident angle for Stem wave formation lies within the range of 13°-14°.For smaller incident angles,both the wave height and width of Stem waves increase monotonically along the wall,with the wave height decreasing as the incident wave height increases,while the wave width exhibits the opposite trend.For larger incident angles,the wave height of Stem waves initially increases,then decreases,and eventually stabilizes,whereas the wave width decreases with increasing incident angle and shows reduced dependence on the incident wave height.