ГИДРОДИНАМИЧЕСКОЕ СОПРОТИВЛЕНИЕ ПРИ ПЕРЕСТАНОВКАХ МОБИЛЬНОГО МАЛОГАБАРИТНОГО ПРИЧАЛА С ЗАПОЛНЕННОЙ ВЫРАВНИВАЮЩЕЙ ЁМКОСТЬЮ
Authors: Чупраков В.О. , Посыпанов С.В. 
Published: February 2025

Приведены краткие сведения о мобильном малогабаритном причале, его преимуществах и технологии перестановок. Дано теоретическое толкование взаимодействия причала с водной средой при перестановках с обоснованным предложением аналитической формулы для расчёта гидродинамического сопротивления. Обоснован набор факторов, определяющих величину коэффициента гидродинамического сопротивления, входящего в упомянутую аналитическую формулу. Предложено полученное по экспериментальным данным уравнение регрессии для расчёта этого коэффициента в исследуемом случае. Приведены результаты анализа влияния основных факторов на гидродинамическое сопротивление перемещению причала при перестановках.

Introduction. Economically viable delivery of wood raw materials from the most remote woodlands can often be provided only by waterborne transport using a network of medium and minor rivers. At the same time, the use of mobile small-sized berths can be very effective. With the berths, it will be possible to manage the transshipment of forest cargo without expensive floating cranes. When the water level in the river decreases, the berth is diverted from the shore with the filled leveling tank, stern part forward. In this case, there is the greatest hydrodynamic resistance to its movement, which is advisable to know, as the boats operating on minor and medium-sized rivers are of small power. No information that allows to determine the specified resistance accurately was found. The goal of the research is to provide the possibility for calculating the hydrodynamic resistance when moving a mobile small-sized berth with a filled leveling tank, and to assess the influence of significant factors on this resistance. The research method provides a theoretical justification of the proposed calculation formula, which includes a coefficient that considers the features of this process. The formula for determining the coefficient is established on the basis of the results of experiments. The influence of determining factors is also estimated by it. Results. The authors found that the share of the friction component in the total resistance was insignificant in the considered case. The shape and wave resistance are predominant. For this reason, a monomial analytical formula is proposed to use. The authors proved that the coefficient of hydrodynamic resistance could significantly depend on the Froude number and relative depth. The experiments were carried out on a physical model made on a scale of 1:20. As a result of regression analysis, authors obtained a second-order equation with an approximation confidence of 0.82. In the analysis, it was found that with a decrease in the relative depth from 2.00 to 1.33, the studied coefficient could increase by 26...36%. With the increase in the Froude number in the range corresponding to full-scale velocities of 0.45...0.85 m/s, it increases by 46...58%. The speed through the Froude number more significantly affects the value of the coefficient. In the analytical formula, the hydrodynamic resistance also has a direct quadratic dependence on the velocity. That is, its influence is clearly predominant. Conclusion. The obtained results provide the possibility for calculating the greatest forces required when moving a berth that is in a floating state, and considering knowledge about the nature and degree of influence of determining factors.