A numerical model is developed to simulate the full hydrodynamic response of ships during lock entry under both constant-speed and fixed-thrust propulsion modes. The model accurately resolves the nonlinear superposition of multiple confined water effects, including shallow-water, bank, blockage, and cul-de-sac channel effects (induced by the lock chamber's closed end), and captures the dynamic transition from standstill to acceleration and subsequent deceleration. A total of 14 representative cases were designed, covering variations in ship speed, water depth and propulsion mode to comprehensively investigate the hydrodynamic characteristics of ship lock entry. Results show that confined water effect markedly increases viscous pressure resistance, with its proportion in viscous resistance reaching up to 90.4% under constant-speed conditions. Under fixed-thrust conditions, the peak viscous resistance in shallow water when water depth-to-draft ratio (h/T) is 1.2 is 437.1% higher than in deep water (h/T = 30), and the lock-entry duration is extended by 44.3%. Initial speed has a pronounced influence on entry efficiency. Compared with a 0 m/s start, an initial speed of 0.15 m/s shortens entry time by 40.5%, while final velocities converge to 0.048 m/s with a reduction of 70.4%. This indicates a dynamic equilibrium effect imposed by the lock chamber flow on ship speed. These findings provide valuable insights for lock design and navigation strategy optimization in confined waterways.
Wang et al. (Thu,) studied this question.