Coupling Model for Real-Time Simulation of a Sailing Ship’s Motion under the Influence of Irregular Waves and Wind

Abstract

The development of the interactive models for coupled dynamics of floating bodies in changing environments and wind-wave-body interactions is of paramount importance. This study presents a computationally cost-effective approach that implements the simplified but physically based submodels combined into a single system. A realistic geometric model of a complex-shaped sailing ship, which is rigged with adjustable sails and steered by a rudder, is selected as the object of numerical research. The irregular wind waves are simulated using in situ records of the sea surface, probability description, and inverse fast Fourier transform. The complicated geometries of a floating object and arbitrary overwater obstacles, as well as a changeable sea surface, are represented as high-resolution triangular meshes. A six-degrees-of-freedom motion model for an immersed rigid body is also integrated. A technique for the computation of wind loads on arbitrary-shaped adjustable sails, a ship’s hull, masts, and superstructures is proposed. The ship-generated waves that propagate and reflect off arbitrary obstacles are modeled using the linearized wave theory in conjunction with the two-dimensional convolution and masking operations, which are applied to the wave height field. A combination of the above approaches allows real-time conjugate modeling of the dynamics of a ship exposed to wind and irregular waves. A real sailing ship and a virtual one are compared using an experimental polar diagram in terms of the speed characteristics.