Вестник МГТУ. 2018, №4.

Пашенцев С. В. Моделирование циклических реверсивных движений судна... functions of y vector. The appeal to the Runge - Kutta integration function Z = rkfixed(y, 0, m, m, P) performs the procedure of solving the system of differential equations. The solution results are interpolated in the matrix Z , which in this case consists of three columns and 2048 rows. The first column contains the current integration time, the other two columns are the vessel velocity v and the screw revolution speed n . These columns are extracted by simple assigmnent from the matrix Z in the form of V and N vectors in the last two lines of Fig. 4. dvl(v,n) .■= {-kV(v> - v ■ ■ki - TT(v.n)) MM dn l(v ,n ,t) := [kM • (Mdv(t.n)) - kQ - QQ(v,n)] 5 P(t7y) := Г 1 M W ) m := 204S k := 0.. m - 1 Z := ikfeed(y,0,in.m.P) & X :=Z Ttk - % :=QQ(vk-Nk) Fig. 4. Differential equations of the ship's movement and the screw rotation, and their integration by means of rkfixed() function Рис. 4. Дифференциальные уравнения движения судна и вращения винта и их интегрирование с помощью функции rkfixed() Solution graphics In Fig. 5 there are two obtained vectors V and N represented graphically. The periodic change in these characteristics of movement is clearly visible, and the rotation speed is ahead of the ship's velocity at the point of transition through the zero values - the engine inertia is less than the vessel one. Thrust and torque are obtained for each T k moment using assignment (9): Fig. 5. The temporal variation in the ship's velocity and the screw rotation speed Рис. 5. Изменение скорости хода судна и оборотов винта во времени 570