Resistance Analysis And Form Factor Prediction Method Of Trimaran

With the development of modern shipbuilding industry and technology to enhance the SWATH,trimaran and composite ship type and other high-performance new ship more and more attention.With the deepening of the understanding of these ships,ship design and construction technology continues to improve,ship performance is more and more perfect.Among them,the trimaran Because of high speed,good seakeeping,large deck area and strong survival ability and other advantages,the rapid development,has been widespread concern in all countries.The causes and composition of resistance analysis and resistance prediction are the key to the optimization of ship type,rapid performance improvement and excellent ship design.In particular,there are complex disturbances between the three hulls of the trimaran.The resistance component is different from that of the conventional single ship.It is especially important to find out the resistance component and forecasting method to accurately predict the ship's resistance.At present,we mainly use the two-factor method and the 1+k method to forecast the ship's resistance.Of which 1+k method needs to determine the the viscous resistance which act on the form factor,Since the form factor is assumed to be for single ship,and the trimaran ship usually has high speed,at the same time,there are complex waves between the hull and viscous flow interference,and the separation between the hull of the body,the the layout of the main body and the side body and ship type changes will lead to resistance components and resistance changes.What are the characteristics of the form factor in the trimaran resistance forecast brought by these changes? For the conventional single-ship form factor selection method is practical,how to select the form factor of the trimaran is currently less studied.In this paper,trimaran 's resistance components were forecast and analysis,discusses the shortcomings of the traditional form factor determination method for trimaran.Starting from the definition of form factor,based on the theory of viscous friction and forecast the Resistance,Study form factor connotation and characteristics.Based on the potential flow theory to predict the wave resistance,determine the form factor.The variation characteristic form factor and method for determining the characteristics of the trimaran,deliberated trimaran speed and layout changes on the sheet body form factor and features.The results show that,at Fr=0.63,for the viscous pressure,CFD direct simulation results are 11.95% larger than the results of the overlay.For the total resistance,the CFD direct simulation results are 5.31% larger than the viscous combined potential flow method.The vertical position of the slice will have a great impact on the wave resistance.In the middle and high speed range,the lateral position of the plate will also have a significant effect on it,the effect of the viscous effect of the fluid on the wave resistance of the tricusics increases with the increase of the velocity.The longitudinal layout of the sheet has a significant effect on the viscous resistance,and when the slice is located in the amidships,the lateral position of the plate has a great influence on it.The form factor shows a fluctuating change with the speed,and the numerical value is much larger than the traditional method.The size and variation of the shape factor of the trinity ship can not be neglected by the influence of the layout of the body.The horizontal layout of the body has an effect on the value of the shape factor,with the increase of Fu Rude number,the vertical layout has a great influence on the numerical and changing trend of shape factor.