Оценка маневренных характеристик электроходов на начальных стадиях их проектирования

Abstract

Надежность и безопасность маневренных операций определяется совместной работой лектроэнергетических установок, движителей и корпуса электроходов. Предложен способ оценки маневренных характеристик электроходов на начальных этапах проектирования. Выявлены параметры пропульсивных комплексов, наиболее значимо влияющие на эти показатели. Разработаны простые математические модели – аналитические зависимости показателей от параметров комплексов. Модели позволяют на начальных стадиях проектирования в условиях ограниченной информации прогнозировать маневренные свойства судов и находить пути их улучшения.

Interest in the use of electric motion in the shipbuilding industry is growing. The main advantages of electric ships are: reliability; economy when operating at reduced speeds; high maneuverability. The reliability and safety of maneuvering operations is determined by the joint operation of the power plant, propulsors and electric ship’s hull. Therefore, the ability to assess the maneuverability characteristics of all components of electric ships’ propulsion complexes at the initial stages of their design is urgent. The search for methods of such an assessment is the goal of this paper. The peculiarity of electric ships’ operation on maneuvers is that the duration of transient processes inthe power plant are commensurable with the duration of the transient processes in ship’s movement. Therefore, the analysis of the operating conditions of the electrical propulsion plant should be carried out in unity with all the components of the propulsion complex. The state of the question. A mathematical model of transient regimes for the analysis of maneuvering operation modes has been developed. It describes the transient regimes of all the components of the complex. The criteria of dynamic similarity – the dimensionless parameters of the system "electrical propulsion plant–propellers–ship’s hull" are revealed. It is these parameters that determine the quality of maneuvering. The result of the study. Simple calculation methods in estimating and predicting electric ships’ maneuverability characteristics at the early stages of designing are necessary. For this purpose, significantly influencing parameters for each quality index were revealed. And then using the methods of active experiment planning, analytical models – the dependencies of the indicators on the parameters of the complex and the significant interaction effects of the parameters – were constructed. The possibilities of using the developed analytical models for estimating the main maneuvering indices are illustrated. At the same time, theerror in the calculation method is also estimated. As the object of comparison, the design of the vessel with frequency-controlled propulsion motors was chosen. Calculation results of the quality indicators of maneuvering by approximate and exact methods are compared to evaluate the error in analytical models. The errors are in the range 3,8-11,7%. They are acceptable for dynamic calculations. The application of the proposed models to find ways of improving maneuverability is illustrated. Conclusions. Convenient methods of evaluation are necessary for an approximate assessment of the basic performance indicators at the initial stages of designing electromechanical systems. Simple analytical models are proposed to assess the maneuvering regimes. Errors in the calculation method are within acceptable limits.