Research On Hydrodynamic Performance Of New Auxiliary Propulsion Device For Ships

With the rapid development of the global economy,trade between countries in the world is becoming more and more frequent,and the demand for maritime trade transportation is increasing.However,with the increasing shortage of non-renewable energy sources in the world,the cost of maritime transportation is getting higher and higher.How to reduce the cost of ships in maritime transportation is becoming more and more important.At present,the main means to reduce the cost of maritime transportation is to reduce the fuel consumption of the ship during transportation.The main ways to reduce the energy consumption of the ship are to reduce the resistance of the ship during navigation and absorb the wave energy around the ship as part of the energy to propel the ship.These two methods generally need to install appendages around the ship without changing the existing ship type.The ship’s energy-saving appendage mainly reduces the resistance of the ship during navigation by improving the flow field around the hull.The device that uses wave energy(wave propulsion device)is to absorb the wave energy around the ship and convert it into energy that propels the ship forward.With the continuous development of CFD technology,the use of CFD numerical simulation technology to predict ship hydrodynamic performance is more and more popular in the shipbuilding industry,which provides technical conditions for the research and improvement of passive wave propulsion devices in this paper.In this paper,based on STAR-CCM + numerical simulation software,NACA0015 hydrofoil is used as a prototype for numerical research,and a passive wave propulsion device with good propulsion performance is proposed,and the device is finally installed on a KCS ship model for numerical simulation research.The main research contents of this article include:(1)The influence of the leading edge raised structure on the hydrofoil thrust performance was studied.In this part,the leading edge of the hydrofoil is raised and numerically simulated based on the NACA0015 hydrofoil.Furthermore,the influence law of the leading edge bulge and its distribution length on the hydrofoil propulsion performance is further analyzed.Finally,a new hydrofoil with better propulsion performance is obtained by combining the simulation results.(2)Taking the new combined auxiliary propulsion device as the research object,the STAR-CCM + software is used to perform the hydrodynamic performance simulation calculation.This section separately calculates the hydrodynamic performance of the hydrofoil with the leading edge protrusion after the float is installed at different water depths,different wave parameters,and different horizontal distances between the float and the hydrofoil.By comparing the average thrust generated by the hydrofoil under various operating conditions,a new form of combination of a hydrofoil and float with a raised leading edge with excellent propulsion performance is summarized and analyzed.(3)Based on the CFD numerical simulation software,the ship model with the new combined auxiliary propulsion device is simulated in the regular wave.In the established three-dimensional numerical wave pool,the resistance of the ship,the propeller thrust performance,the response to the ship’s motion and the thrust performance of the wave auxiliary propulsion device under the same working conditions were calculated for the KCS bare ship and the new wave auxiliary propulsion device.Finally,the comparative analysis and calculation results verify that the new wave-assisted propulsion device can not only provide auxiliary thrust for the ship,but also improve the motion response of the ship sailing in the waves.