Research On Multi-Objective Optimization Method Of Ship-Engine-Propeller Matching

Traditional ship-engine-propeller matching is generally conducted with the single goal of propeller open water efficiency,in order to save fuel cost during the ship voyage.In recent years,the increasingly stringent international emission regulations have placed higher requirements on the design of ship propulsion systems.The proposed multi-objective optimization-based ship-engine-propeller matching design method can realize the concurrent design of ship economy,emission and propeller performance,with the optimal comprehensive index can be obtained in the early design stage,shortening the period of subsequent calibration and iterative optimization.Based on the energy chain of the ship propulsion system and the respective working characteristics of the ship,machine,and propeller,a ship-engine-propeller matching design network has been established in this paper.According to combinations of the input and output design parameters,three types of matching design conditions are summarized,representing different scenarios of ship-engine-propeller matching in real design process.The accuracy of the matching method has been verified by the benchmark data.The performance indicators evaluating ship operations has been quantified in this paper,summarizing the calculation model of important indexes,like the fuel consumption,ship energy efficiency design index,and NOx emissions.Furthermore,a sensitivity analysis of these performance indicators under different arrangements of ship speed and propeller diameter has been conducted,in order to figure out the changing trend and extent of the ship operation performance indicators.As for the propeller performance indicators,the propeller performance check method based on the mature cavitation check method and the strength check process is sorted out,and verified by the benchmark data.Based on the calculation model of ship and propeller performance indicators,a multi-objective optimization for ship-engine-propeller matching is proposed to achieve an overall matching design that takes ship economy,emissions and propeller performance requirements into account.In order to improve the ability to solve discrete,high-dimensional,and nonlinear matching problems,genetic algorithm is adopted to solve multi-objective optimization problems.A multi-objective decision-making evaluation method based on the coupling weight of the analytic hierarchy process and the entropy weight method is proposed to realize the scientific decision of the optimal solution among multiple groups of effective solutions.The multi-objective optimization for ship-engine-propeller matching design method has been proposed in this paper,based on a clear ship-engine-propeller mathematical model,and combined with multiple performance indicators,in order to achieve the overall and optimized design.In this paper,an open multi-device,multi-objective optimization framework is provided for the design of ship propulsion systems,which has great influence on the field of integrated ship design.