STUDYING THE WIND AND WAVE EFFECTS INFLUENCE ON THE SHIP DURING THE TRANSITION TO DRIFT

Abstract

Most of the calculations that have to be performed when solving navigational tasks are approximate, because of the assumptions that are made in this case, as well as approximate values of the quantities that are used in the calculations. Algorithms for practical calculations to take into account the disturbances influence on the maneuvering process are not available for all types of disturbances. The result of the wind action on the ship is difficult to determine exactly. With a weak headwind, the ship loses little speed, and slightly increases it when such a wind is from the stern. With a strong wind, the ship’s course decreases both with a headwind and with a tailwind. The reason for this is the wave action, which develops with the wind and increases the resistance to the ship movement. The issue of studying the wind influence on the ship seaworthiness is considered and the task of creating a model for taking into account the ship behavior when observing its drift without running is set in the paper. At solving this problem, the methods of ship theory (for analyzing the dynamics and kinematics of the ship), mathematical modeling, the theory of static analysis and full-scale experiment are used. During the full-scale experiment, the vessel behavior when mooring to it during catching process from a purse seine is considered, and observations of drift without running on a medium fishing freezer trawler during fishing with the purse seine in the Black Sea are also made. The performed studies allow us to obtain data for determining the speed and angle of drift when planning a mooring for receiving a catch in the case of steady drift. This allows us to determine the value of the ratio of dimensionless coefficients of transverse aero and hydrodynamic forces for the case of steady drift.