Вестник МГТУ. 2018, №4.

Пашенцев С. В. Моделирование циклических реверсивных движений судна... Table. C T and CQ coefficients of the screw for all the angle в quadrants Таблица. Коэффициенты СТ и CQ винта для всех четвертей угла в v / n +1 / +1 -1 / +1 -1 / -1 +1 / -1 Angle в , rad. 1.341 1.801 4.482 4.942 Lammeren CTL -0.875 -0.754 0.942 0.710 CQL -0.132 -0.109 0.149 0.104 Lammeren Shifted CTL 0.214 0.114 -0.176 -0.100 CQL 0.033 0.021 -0.028 -0.020 Lammeren Smooth CTL 0.324 0.110 -0.265 -0.114 CQL 0.037 0.024 -0.037 -0.021 i X Fig. 2. Shift-modified Lammeren's curves of the screw action Рис. 2. Модифицированные сдвигом кривые действия винта Ламмерена Fig. 3. Modified and smoothed Lammeren's curves o f the screw action Рис. 3. Модифицированные и сглаженные кривые действия винта Ламмерена Differential equations of the problem The solution is made in MathCad which provides ample opportunities for integrating systems of differential equations and then obtaining high-quality graphic materials. In fact, we are to integrate a system of two differential equations. The first one is the equation of rectilinear motion of a vessel which is affected by the hydraulic resistance force and the screw thrust. The force of resistance will be considered proportional to the square of the movement speed and always opposed to the movement. It is the force of the screw thrust that we find with the help of the modified and smoothed Lammeren's curve. To do this, CT coefficient of the propeller thrust is taken from the curve, then according to Lammeren the thrust is found using the formula: ТТ = (1 - Т) • СТ • ( v 2 + (0.7 n wD) 2 ) . (3a) 8 568