Research On Manuverability Of Planing Craft In Wind, Wave & Current Environment

The work of this thesis is mainly concentrated on researching the manuverabilty of planing craft in wind, wave & current environment, establishing maneuvering motion mathematical model, and predicting the manuverabilty of planing craft in calm water and wind, wave & current environment.At First, This paper established a new coordinate system included the translation coordinate system following ship, and gave the coordinate transformation relation. In new coordinate system, the author derived the six freedom maneuvering motion equation of planing craft in calm water. After establishing equation, based on ideas of the MMG separation model, this paper divided external forces added on the craft into Inertial hydrodynamic force(included moment), Viscous hydrodynamic force, Damping force, Restoring force, Lift force and Water-jet force. After studying the mechanism of the forces, this paper gave the mathematical models of each force. At the same time, the author studied the differences between water-jet propulsion system and conventional propeller propulsion, then gave the mathematical model of water-jet. Hereto, a holonomic maneuvering motion mathematical model of planing craft in calm water was established.Then, based on the assumption of stationary wind, regular wave and uniform current, the author researched the wind, wave and current disturbing force/moment, and added them to the motion equation of craft in calm water. Consequently, a simplified maneuvering motion mathematical model of planing craft in wind, wave & current environment was established.At last, based on the previous mathematical model, the author. established a numerical simulation program of the maneuvering motion equation. The program used 4th order Runge-Kutta method to solve the equation. In the solving process, all the parameters of the motion were time variance. Via processing the datas of numerical simulation, we can gain the predicting results of maneuverability of planing craft in calm water and wind, wave & current environment.In a word, this thesis established six freedom maneuvering motion mathematical model to simulation the manuverabilty of planing craft in wind, wave & current environment, which tried to combine the ship maneuverability and seakeeping, and break the conventional boundary between previous two fields. this paper layed a foundation in researching the manuverabilty of planing craft in wind, wave & current environment.