Modeling the influence of wind on ship circulation elements

Abstract

When solving a number of practical problems of navigation and ship maneuvering, it is necessary to take into account the effect of wind on the parameters of the ship motion, including curvilinear motion, in particular, on circulation. There is very little information on this problem, especially in terms of quantitative estimates of the wind impact on circulation elements. Based on this, the purpose of this work is to study the effect of wind on the circulation elements based on mathematical modeling and to determine quantitative estimates of this effect when changing such factors as wind speed and heading angle, ship length and rudder angle. The simulation is carried out on a certified navigation simulator Transas NT Pro-5000. The mathematical model of vessel movement and wind effect used in this simulator is presented in the paper. A description of three simulated container ships with similar aerodynamic characteristics is given for the various heading angle and velocity of the wind before the start of the turn. In some experiments, the rudder angle is changed. The results of the simulation are presented in tabular and graphical forms. Quantitative estimates of the displacement of the turning points on the circulation by 90°, 180°, 270° and 360° at wind influence from the corresponding points of circulation in the absence of wind. The graphical dependences of these displacements on the heading angle of the wind and their analytical approximations are presented. The ranges of the wind heading angles at which the maximum effect of the wind on the circulation elements is observed are established. Quantitative estimates of the inversely proportional dependence of the circulation elements on the ship length are calculated. The hypotheses of the other authors about the direction of displacement of the circulation curve under wind action are tested. To verify the validity and reliability of the results obtained, it is necessary to perform similar studies using other mathematical models and natural experiments.