Objective  There are multiple operation conditions for ships navigation in inland river waterway, such as sailing downstream, upstream as well as in rapid stream, but the traditional ship-engine-propeller matching method can only ensure that the inland ships meet the design requirements when they travels upstream. Under downstream conditions, the ship propulsion's efficiency and energy utilization rate of main engine are both low, resulting in high fuel consumption and less cost-effectivness. To this end, the optimal design of ship-engine-propeller matching for the inland ships under multiple conditions is carried out.

  Methods  First, the parameters of an inland ship's propulsion system under various conditions are designed, and the results are compared to ascertain the influence of each design parameter on the overall propulsion system. Then, the design process of the propulsion system is analyzed, and a mathematical model is established with navigation cost and propulsion system efficiency as the objective functions, and the design parameters of the propeller, main engine power and ship speeds (upstream & downstream) as variables. Finally, the main engine power and design parameters of propulsion system are determined balancing both economy and efficiency using the NSGA-II algorithm.

  Results  The design parameters obtained using this method are easily adapted to the traffic environment of inland ships, making them more economical.

  Conclusion  The results of this study can not only provide design tools for the selection of ship propulsion systems, but also provide a theoretical basis for its practical application.