Key Technologies Of Ship Motion Simulation Base On Sea State

The main work of his paper is establish the ship motion simulation base on sea state, and combine with an existing simulation system for submarine supporting and lifesaving operation, improve the authenticity of this simulate system.In the aspect of ship hull motion, this paper chooses strip method based on frequency domain as motion model. First, introduce the related theory, including how to obtain ship hydrodynamic coefficients at different frequency, how to calculate ship force and moment in waves, how to build the ship motion differential equations at last. This paper's work is real-time solve the equations with Runge-Kutta metho in simulation program, calculate ship's heaving and pitching data at any moment.In the aspect of sea surface motion, this paper chooses the sea spectrum model and Gerstner model to build sea surface. Related theories including, the principle of sea spectrum and how to calculate wave parameters on sea surface with sea spectrum, how to calculate water parcel displacement on sea surface with Gerstner model, and the related knowledge on wind scale and sea state level. This paper correspond sea state to three-one average wave height approximately, determines upper limit and lower limit of the main wave frequency at different sea state; Then designs proper net, calculate water parcel motion, and renders a dynamic sea surface.Base the research of ship motion and sea state, this paper matches the data of two algorithms, designs calculate program, writes codes, realizes ship motion simulation base on sea state; Analyzes the program construct of the existing simulation system for marine rescue operation, determines the proper position, and combined with ship hull motion simulation base on sea state as a module, makes the simulation running normally after the new function has been inserted; Optimums the codes and models of simulation system, makes the running speed almost invariant after more function has been added.After running simulation program, this paper confirm that wave has limited influence for the safety of submarine supporting and lifesaving operation at sea state 4 by observing the situation of rescue ship executes operation on sea surface, the process of operation is safe.The innovations of this paper are, first directly associate sea state and ship hull motion to build simulation, first combine the simulation of ship hull motion in sea wave with a simulation system with work flow and multiple entities, improves latter's authenticity. The research result of this paper could be used in simulation of other ship types, and has obvious strategic significance and practical value at application prospect.