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

Methods The SST k-ω turbulence model and volume of fluid (VOF) method were employed to analyze free surface effects on propeller open-water characteristics. A Seiliger-cycle-based mean-value engine model simulated steady/dynamic operations of the main engine, obtaining thermodynamic parameters. The integrated power system model investigated dynamic responses during ship acceleration in waves.

Results Under wave conditions, alterations in propeller immersion depth result in a maximum thrust reduction of 18.34%. This reduction affects the stability of propeller thrust output and poses a threat to the operational safety of the vessel. During the acceleration phase of the ship's main engine, exhaust temperature and excess air ratio fluctuate significantly due to wave disturbances, reaching maximum values of 1 370 K and 0.558 9, respectively. These values exceed the safe operational limits for the main engine. Consequently, measures must be implemented to alleviate the impact of waves on the main engine's performance to ensure the safety and efficiency of the ship's operation.

Conclusions The proposed method accurately predicts dynamic performance variations in waves by coupling hydrodynamic and thermodynamic models, revealing parameter interaction mechanisms. Combined with operational boundary analysis, it provides theoretical support for developing control strategies under extreme sea conditions.