The Study Of Waterjet Propulsion And Its Control Technique

Nowadays,the waterjet is one of important propulsion techniques for ships. It is applied to many high-performance ships for its high propulsive efficiency, lower noise and vibration,and simple transmission machine.In the paper,the application of waterjet on a Small Water-Plane Area Twin Hull(SWATH) is researched.The design of waterjet propulsion and its hydraulic system simulation are studied.It is contributed to extension and application of waterjet propulsion. At the same time,it has the engineering significant of conducting to design the hydraulic system of waterjet.In the paper,the researches have been done as follow.1.The basic principle of waterjet propulsion is researched.On this basis,the hydrodynamic resistance characteristics of SWATH are analyzed.And then, according to the SWATH ship example,its hydrodynamic resistance characteristics are studied.Except that,the hydrodynamic resistance characteristics and basic parameters of waterjet propulsion device are elementarily calculated.2.Through analyzing requirements of maneuver and control for waterjet propulsion device,the hydraulic servo system is mainly studied.The mathematical models of reversing and steering hydraulic servo systems are established.And some associated characteristics influencing the system performance are discussed.3.The steering servo system is analyzed and designed in detail taken the steering mechanism as an example.To consider hydraulic system nonlinear factors,the AMESim simulating model of steering servo system is built up on the basis of AMESim simulating system.Through the simulation,the desire tracing characteristics are obtained.4.After studying requirements for waterjet propulsion device,such as system functions,electric control and monitor etc,the elementary scheme to design full digital monitor and control electric system is given.The electric system disturbances of waterjet propulsion device are discussed,and some methods are provided to avoid it.These are beneficial references for really designing electric control system of waterjet propulsion device.