Research on the suppression method of bow wave plunging breaking for high-speed ships

• The bow wave breaking characteristics of high-speed ships are investigated. • The evolution process of bow wave breaking is analyzed. • An appendage for suppressing the bow wave breaking of high-speed ships is proposed. • The appendage can significantly suppress the bow wave breaking of high-speed ships. The plunging breaking of bow waves on high-speed vessels is one of the primary causes of bubble wakes. Reducing the severity of bow wave plunging breaking helps mitigate bubble wake formation, thereby enhancing vessel stealth. This study aims to mitigate bow wave breaking of high-speed displacement ships with a Froude number (Fr) between 0.4 and 0.5. The Delayed Detached Eddy Simulation (DDES) method is employed to numerically simulate the bow wave plunging breaking phenomenon. Initially, simulations are conducted at three speeds corresponding to Fr = 0.41, 0.45, and 0.494. The results indicate that the breaking behaviors at these three high speeds exhibit certain similarities, all characterized by plunging breaking with two distinct scars and three plunging events clearly observed. Taking Fr = 0.45 as a representative case, the origin and structure of the water layer involved in the bow wave plunging breaking process are analyzed based on streamlines. It is determined that the suppression of bow wave plunging breaking should primarily target the first plunging event, and accordingly, an appendage device for suppressing the first plunging of bow waves is proposed. Numerical simulation results demonstrate that the proposed appendage can significantly suppress bow wave breaking at Fr = 0.45. Furthermore, by adjusting the vertical installation position of the appendage, notable suppression is also achieved at Fr = 0.41 and Fr = 0.494. Finally, the influence of the geometric parameters of the appendage is investigated. The findings of this study provide valuable insights and a potential approach for the suppression of bow wave plunging breaking.