Study On Resistance Performance Of 30000 DWT Multi-Purpose Vessel Based On CFD Theory

In response to economic,societal and technical,including changes in global environmental issues and relevant laws and regulations,new ship types and practical applications continue to be developed.The impact of these changes on ship design depends on the reliable assessment of the ship's hydrodynamic performance,and the ship's resistance performance is the basis and key content of the research on hydrodynamic performance research.The research methods of ship resistance performance are divided into three kinds: ship model test,approximate estimation method and numerical simulation calculation of viscous flow around the hull based on computational fluid dynamics(CFD).With the continuous improvement of computer capabilities and a series of breakthroughs in high-efficiency numerical calculation methods,CFD has made considerable progress in the field of ship design.Its advantages in economy,timeliness and reliability are becoming more and more obvious.It has become a powerful tool for the calculation of hydrodynamic performance and ship optimization and innovation design.On the basis of this,the study of ship resistance changes under the condition of trim loading of multi-purpose ships provides a theoretical basis for real ship loading optimization.The main content of the thesis is to use the numerical calculation method based on CFD,to calculate the resistance performance of the 30,000 DWT multipurpose vessel,and to compare and analyze the data obtained from the ship model test,and verify the rationality and accuracy of the numerical calculation method of the 30,000 DWT multipurpose vessel.Firstly,the background and main research methods of ship resistance performance research are summarized and reviewed.Then,the development history of CFD technology in ships at home and abroad and the research progress of resistance performance based on CFD are introduced in detail.Secondly,the basic theory of ship resistance is introduced,including the classification of ship resistance and the resistance coefficient,and the method of resistance solving based on the ship model test.Then the basic theory of computational fluid dynamics and the numerical simulation method involved in the calculation of the resistance CFD of 30,000 DWT multipurpose vessel are introduced in detail.Thirdly,using STAR-CCM+ software,overlapping grid technology was used to analyze the resistance performance of a multi-purpose ship considering the free coupling between liquid surface and dynamic fluid solid interaction,and the hull resistance values at different speeds were obtained.The numerical calculation results and towing tank tests were also performed.The friction resistance,pressure resistance coefficient,ship heave,and pitch change in the data were compared and analyzed to verify the reasonableness and reliability of the meshing,turbulence model and numerical setting.At last,according to the characteristics of the loading condition of the 30,000 DWT multipurpose vessel,calculates and analyzes the ship's resistance performance under different trimming conditions,and under the condition of keeping the ship's designed deadweight constant,the best trim angle and reduction resistance of the multi-purpose vessel at different speeds are obtained.The theory and mechanism of ship resistance reduction under trim position is compared and analyzed,provides a reference for the loading plan of multipurpose vessels in actual navigation.