Objective This study proposes an integrated simulation method for marine power systems that combines the hydrodynamic characteristics of the propeller with the thermodynamic properties of the marine diesel engine, aiming to reveal the influence of wave disturbances on the performance of the ship power system.

Method The SST k-ω turbulence model and volume of fluid (VOF) method were employed to analyze the influence of free surface height on the propeller's open-water characteristics. A Seiliger-cycle-based mean-value engine model was used to simulate both steady and dynamic operations of the main engine, allowing for the calculation of the main engine's thermodynamic parameters and their variation laws. The integrated power system model was adopted to investigate the dynamic response characteristics of the power system during ship acceleration in waves.

Results Under wave conditions, changes in the propeller's immersion depth result in a maximum thrust reduction of 18.34%, which impairs the stability of the propeller's thrust output and threatens the operational safety of the vessel. During the acceleration phase of the ship's main engine, the exhaust temperature and excess air ratio fluctuate significantly due to wave disturbances, reaching maximum values of 1 370 K and 0.558 9, respectively, which exceed the safe operational limits of the main engine.

Conclusion The proposed method accurately predicts the variation laws of the dynamic performance of the ship power system in waves by coupling the propeller hydrodynamic model and the diesel engine thermodynamic model, revealing the coupled response characteristics between the propeller hydrodynamic parameters and the main engine thermodynamic parameters. Combined with the analysis of the main engine's operational boundaries, it provides theoretical support for the research on control strategies of the ship power system under extreme sea conditions.