Influence Of Energy Saving Device Propeller Boss Cap Fins On Ship-Engine-Propeller Matching

With the increasingly stringent emission regulations of the International Maritime Organization and carbon peak and neutrality goals of China,energy conservation and emission reduction has become a research hotspot in the field of ship design.Propeller boss cap fins(PBCF)energy-saving device and ship-engine-propeller matching research reduce ship energy consumption from the perspective of propeller energy saving and reasonable matching energy saving of propulsion system.These energy-saving methods are widely used because they have the advantages of small workload of ship refitting,flexible application and good energy-saving effect.Based on the independent study of the two energy-saving methods,this paper studies the influence law of the installation of PBCF on the matching relationship of the propulsion system,and puts forward new requirements for the optimal design of PBCF from the perspective of propulsion system integration.Based on the computation fluid dynamics(CFD)method to calculate the hydrodynamic characteristics of propeller and PBCF,compare and analyze the pressure field and flow field distribution of propeller before and after PBCF addition,and the energy-saving mechanism of PBCF is obtained,and then calculate the open water characteristics to provide support for the subsequent research on ship-engine-propeller matching.Then,this paper uses the simulation based design(SBD)technology to optimize the design parameters of PBCF,obtains the open water characteristic curve of propeller under the optimal design parameters of PBCF.According to the energy transfer relationship of ship propulsion system and the working characteristics of ship,engine,propeller and PBCF,establish the ship-engine-propeller matching design mathematical model,and use the simulation software to build a variable floating ship-engine-propeller matching platform which can design the PBCF energy-saving device,verify the accuracy of the matching platform according to the real ship data.Finally,the energy-saving device of PBCF is combined with ship-engine-propeller matching,study the effects of different design parameters of PBCF on the power and speed of main engine of propulsion system,it also provides a basis for the design of PBCF from the perspective of propulsion system integration.In this paper,according to comparing the changes of propeller flow field before and after PBCF addition to reveal the energy-saving mechanism of PBCF,and research the basis of PBCF parameter optimization design.Taking the hull trim energy-saving and PBCF energy-saving device as the starting point,this paper studies the influence of the change of its original working characteristics on the ship-engine-propeller matching of the propulsion system after adopting the hull and propeller energy-saving technology.The optimization design of PBCF is combined with ship-engine-propeller matching,The effects of the main design parameters of PBCF on the main parameters of the system,such as propeller efficiency and main engine power of the propulsion system,are obtained,it provides a more complete evaluation index of energy-saving effect and optimization of design parameters for the design of PBCF in ship-engine-propeller matching.