Research On The Hull Form And Resistance Performance Of Trimaran Planing Hull

This paper is originate from research on the Hull form and Powering performance of Unmanned Trimaran Planing Hull, which is the fund project of Multihull Ship Technology Key Laboratory of Fundamental Science for National Defense. It aims at solving the problem of how to select the multiple unmanned surface vehicle's hull form through this study of unmanned trimaran planing hull's design and resistance performance. The first stage is mainly about analyzing the latest ASW USV of United States navy, and designing the high payload trimaran planing hull's hull form based on a great deal of analysis of similar ship's hulls and their responding performances. And then model tests are carried out in different displacement and longitudinal position of center of gravity. The results show that the designed hull with excellent performance. Through the first stage study, the approximately resistance performance is known, and the role of the channel in powering performance and longitudinal stability is clear. At the second stage, using Round Britain record breaker's hull as mother ship, five different planing surfaces are designed which are non-spray and non-stepped, spray and non-stepped, spray and three-stepped, spray and one-stepped and spray and oblique two–stepped. Hydrodynamic performance is undertaken after analyzing the data obtained from tank test with models in different displacements and longitudinal positions of center of gravity. Test results also show that the resistance curve of fast trimaran planing hull is with two obviously peaks which is different from the ordinary planing hull, the channels in both sides not only improve the speed limit but also make it stay in well attitude in high speed, the hydrodynamic performance can be greatly influenced by main hull's length/beam ratio and if the beam is too narrow, the resistance will increase. After the trim angel and wetted length are calculated with SIT method adding channel's friction to total resistance, resistance is estimated in that attitude. And the results demonstrate that the precision satisfies the engineering requirements in a certain speed range. Then samples are gotten from the experiment results to train the BP neural network with the BP neural network toolbox of MATLAB software. After that the trained BP neural network is used to calculate the resistance. Errors between simulation results and experimental results are very small.In this paper, it is mainly about the research on the hull form and resistance performance of trimaran planing hull based on tank experiments, but the force on the trimaran planing hull which sails in the dual medium is complex and resistance performance is influenced by many parameters, so the study still belongs to the trimaran planing hull's concept design and can supply references to the further study on the trimaran planing hull's hull form and hydrodynamic performance.