Optimal Matching Research Of Propeller Boss Cap Fins With Specific Parameters

With the issues of increasing energy-intensity and rising oil prices, improving the energy efficiency of ships based on the original ship construction program has become an effective means to deal with the issues for China’s shipbuilding industry. Researches start to focus on propeller boss cap fins (PBCF) as a kind of propeller energy-saving devices.However, the designs of PBCF mostly rely on the experiments of multi-model to determine the best option, while the main parameters which affect PBCF’s efficiency are given qualitatively. According to the PBCF’s efficiency influenced by the best range of parameters which has been advanced by some scholars, this thesis determines the selection method of PBCF’s parameters by comparing the impact of different axial position and installation angle for open water efficiency.The PBCF’s matching parameters of DTMB P4119propeller and model are determined with this method. Moreover, a series of numerical simulation is calculated by Fluent at different advanced coefficients under which efficiency gains can be achieved0.93%-2.86%.Propeller coordinate transformation program can be able to transform two-dimensional coordinates of each leaf section to point into three-dimensional coordinates based on the basic parameters of propeller and the size of blade sections have been known. Furthermore, the method of setting PBCF’s parameters is applied in this paper to determine the PBCF’s matching parameters of MAU4-55propeller. Hydrodynamic performance of PBCF is simulated by Fluent in three different pitch ratios whose results show that the propeller efficiency can be increased by0.2%～1.72%.Setting method of PBCF’s parameters is determined by the DTMB P4119propeller which can not only improve the efficiency of the DTMB P4119propeller, but also be applied to MAU4-55propeller to increase efficiency. In conclusion, setting method of PBCF parameters in this paper is feasible and can be popularized.