scholarly journals Mathematical model of the dynamics of a hydrofoil vessel as a complex technical system

2021 ◽  
pp. 168-178
Author(s):  
Д.А. Скороходов ◽  
Ю.Е. Крылов ◽  
А.Л. Стариченков
Keyword(s):  
Mathematical Model ◽  
Unified Modeling ◽  
Modeling Environment ◽  
Phase Coordinates ◽  
Electrohydraulic Drive ◽  
Linearized System ◽  
Complex Technical System ◽  
The Mathematical Model ◽  
Output Indicators ◽  
Disturbed Motion

Определена структура единой среды моделирования, состоящая из трёх блоков: блок, где задаются или формируются значения исследуемых параметров, влияющие на выходные показатели судна, как объекта моделирования, блок представляющий собой ядро единой среды моделирования и блок, где формируется совокупность тех или иных показателей, подлежащих анализу. Определена математическая модель динамики возмущенного движения СПК, при этом использованы следующие системы координат: земная прямоугольная горизонтальная правая, связанная с судном прямоугольная правая и вспомогательная нецентральная прямоугольная правая. Определены основные допущения математической модели. Представлены уравнения динамики судна на подводных крыльях в общем виде и определены силы и моменты, действующие на судно на подводных крыльях в крыльевом режиме движения. Гидродинамические силы и моменты, возникающие на каждом из крыльевых устройств, определены расчетным путем. Работа движителей моделируется заданием среднего упора, направленного по оси вала движителя и параллельного диаметральной плоскости судна. В модели динамики предусмотрена возможность задания аэродинамических сил и моментов, действующие на СПК в крыльевом режиме. Разработана математическая модель электрогидравлического привода, состоящая из суммирующего устройства, электрогидроусилителя и силового интегрирующего привода, охваченных общей обратной связью по положению и скорости перемещения, а также модель системы управления движением, которая является одной из важнейших подсистем СПК, формирующей алгоритмы управления, поступающие на входы ЭГП соответствующих ИО, расположенных на несущих поверхностях КУ. При решении некоторых задач, связанных с проектированием СПК и его технических систем, особенно для получения оценочных значений фазовых координат судна на начальных этапах проектирования или решения специальных задач, разработана линеаризованная система дифференциальных уравнений объекта. The structure of a unified modeling environment has been determined, which consists of three blocks: a block where the values of the studied parameters are set or formed, which affect the output indicators of the vessel as an object of modeling, a block that is the core of a unified modeling environment and a block where a set of certain indicators is formed. analysis. A mathematical model of the dynamics of the disturbed motion of the SPK was determined, with the following coordinate systems used: earth rectangular horizontal right, rectangular right connected to the ship and auxiliary off-center rectangular right. The basic assumptions of the mathematical model are determined. The equations of the dynamics of a hydrofoil ship in general form are presented and the forces and moments acting on a hydrofoil ship in the wing mode of motion are determined. The hydrodynamic forces and moments arising on each of the wing devices are determined by calculation. The operation of the propellers is modeled by setting the middle stop directed along the axis of the propeller shaft and parallel to the diametral plane of the vessel. The dynamics model provides for the possibility of setting aerodynamic forces and moments acting on the HFV in the wing mode. A mathematical model of an electrohydraulic drive has been developed, consisting of a summing device, an electrohydraulic amplifier and a power integrating drive, covered by a general feedback on the JJposition and speed of movement, as well as a model of a motion control system, which is one of the most important subsystems of the SPC that forms control algorithms entering the EGP inputs of the corresponding EUT located on the bearing surfaces of the KU. When solving some problems related to the design of the HFV and its technical systems, especially for obtaining the estimated values of the phase coordinates of the vessel at the initial stages of design or solving special problems, a linearized system of differential equations of the object was developed.

scholarly journals Probabilistic analysis of getting into in restricted area by unmanned aerial vehical

2019 ◽  
pp. 46-54
Author(s):  
A. A. Lobaty ◽  
Y. F. Yatsyna ◽  
V. Y. Stepanov ◽  
A. Y. Bumai
Keyword(s):  
Mathematical Model ◽  
Unmanned Aerial Vehicle ◽  
Probabilistic Analysis ◽  
Stochastic Equation ◽  
Random Structure ◽  
Restricted Area ◽  
Phase Coordinates ◽  
Probability Densities ◽  
Aerial Vehicle ◽  
The Mathematical Model

The probabilistic analysis of crossing by an unmanned aerial vehicle (UAV) of the boundary of the no-fly area is solved. Condition of stating of the fact of the violation of the boundary of the restricted area is to stand of UAV within the area during a specified time. The substantiation of the mathematical model to research through linearized vector stochastic equation is carried out. The problem is solved by applying the theory of Markov processes of random structure with absorption of realizations at the boundary of a given area. Particularity of the approach is the contemporaneously consideration of two probability densities of the distribution of phase coordinates that describe the boundary conditions. In this case, two equations systems are solved for probabilistic moments: taking into account the absorption of realizations and without taking into account the absorption. The probability of an object gets into specified area and do not leave one during the time that necessary to notice the unmanned aerial vehicle at the restricted area.

Sectionalizing and Redundancy of the 0.38 kV Ring Electrical Network

2019 ◽  
Vol 8 (4) ◽  
pp. 15-38 ◽  
Author(s):  
Alexander Vinogradov ◽  
Alina Vinogradova ◽  
Vadim Bolshev ◽  
Alexander Ivanovich Psarev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Load Transfer ◽  
Power Line ◽  
Electrical Network ◽  
Phase Coordinates ◽  
The Mathematical Model ◽  
Voltage Indicator

The use of power line sectionalizing and power line redundancy in 0.38 kV networks entails the need to take into account the fact that currents and voltages can vary significantly at different points of the network. The article proposes a mathematical model to solve this problem. The mathematical model is based on the method of phase coordinates. Using mathematical modeling, the article determines the voltages and currents in the sections of the backup line after the automatic load transfer switch is activated. The article also proposes an improvement in the scheme of the power line sectionalizing unit. The sectionalizing unit scheme is suggested to be modified with a bypass circuit and the installation of a voltage indicator for signaling the voltage presence on the lower contacts of the switch.

scholarly journals Research of a mathematical model for designing a barge-towing complex for the Republic of the Union of Myanmar

2021 ◽  
pp. 82-87
Author(s):  
Т.А. Апалько ◽  
М.Х. Най
Keyword(s):  
Mathematical Model ◽  
Random Search ◽  
Computer Experiment ◽  
Functional Constraints ◽  
Criterion Function ◽  
Complex Technical System ◽  
The Republic ◽  
The Mathematical Model ◽  
Inland Water Transport ◽  
Program Modules

В статье описана математическая модель проектирования барже-буксирного комплекса с учётом особенности эксплуатации в условиях Республики Союз Мьянма. В статье исследуются особенности ББК как объекта оптимизации, описана математическая модель ББК, отображается его как сложную техническую систему. В рамках модели приведены математические зависимости и алгоритмы для определения элементов теоретического чертежа, мощности главных двигателей, для решения некоторых вопросов общего расположения с учетом расстояния главных водонепроницаемых переборок корпуса, для расчета нагрузки и устойчивости. Метод комплексной оценки эффективности применения барже-буксирного комплекса на стадии технико-экономического обоснования проекта в условиях развивающихся стран, в частности в условиях Республики Союз Мьянмы. В результате работы были полностью определены параметры основных типов барже-буксировочных комплексов для перспективной системы внутреннего водного транспорта Республики Союза Мьянма. На базе методов случайного поиска создан алгоритм оптимизации элементов ББК, решающий задачу математического программирования с процедурным характером функции критерия и функциональных ограничений. Математическая модель и алгоритм оптимизации реализованы в виде программы для обеспечения компьютерного эксперимента. Программа, реализующая математическую модель проектирования ББК, состоит из отдельных программных модулей, что облегчает ее совершенствование в анализе результатов решения задачи. Создан программный комплекс с использованием языка программирования Паскаль в среде Delphi для обеспечения автоматизирования проектирования. Указанные программы могут быть использованы в исследовательском проектировании на начальных стадиях проектирования. The article describes a mathematical models for designing a barge-towing complex, taking into account the peculiarities of operation in the conditions of the Republic of the Union of Myanmar. The article examines the features of the BBK as an object of optimization, describes the mathematical model of the BBK, displays it as a complex technical system. Within the framework of the model, mathematical dependencies and algorithms are given for determining the elements of the theoretical drawing, the power of the main engines, for solving some issues of the general location, taking into account the distance of the main watertight bulkheads of the hull, for calculating the load and stability. The method of comprehensive assessment of the effectiveness of the use of the barge-tow complex at the stage of the feasibility study of the project in the conditions of developing countries, in particular in the conditions of the Republic of the Union of Myanmar. As a result of the work, the parameters of the main types of barge-towing complexes for the prospective inland water transport system of the Republic of the Union of Myanmar were fully determined. On the basis of random search methods, an algorithm for optimizing the BBK elements is created, which solves the problem of mathematical programming with the procedural nature of the criterion function and functional constraints. The mathematical model and the optimization algorithm are implemented as a program to provide a computer experiment. The program that implements the mathematical model of the design of the BBK consists of separate program modules, which facilitates its improvement in the analysis of the results of solving the problem. A software package was created using the Pascal programming language in the Delphi environment to provide design automation. These programs can be used in research design at the initial stages of design.

scholarly journals Modeling and Stability Analysis of Wedge Clutch System

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jian Yao ◽  
Li Chen ◽  
Chengliang Yin
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Piecewise Linear ◽  
Wedge Angle ◽  
Stable Condition ◽  
System A ◽  
Actuation System ◽  
Linearized System ◽  
The Stability ◽  
The Mathematical Model

A wedge clutch with unique features of self-reinforcement and small actuation force was designed. Its self-reinforcement feature, associated with different factors such as the wedge angle and friction coefficient, brings different dynamics and unstable problem with improper parameters. To analyze this system, a complete mathematical model of the actuation system is built, which includes the DC motor, the wedge mechanism, and the actuated clutch pack. By considering several nonlinear factors, such as the slip-stick friction and the contact or not of the clutch plates, the system is piecewise linear. Through the stability analysis of the linearized system in clutch slipping phase, the stable condition of the designed parameters is obtained asα>arctan⁡(μc). The mathematical model of the actuation system is validated by prototype testing. And with the validated model, the system dynamics in both stable and unstable conditions is investigated and discussed in engineering side.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

RESEARCH OF INDICATORS OF A VEHICLE WITH A DIESEL WORKING ON DIESEL AND DIESEL GAS CYCLES USING THE MATHEMATICAL MODEL

2020 ◽  
pp. 14-19
Author(s):  
Serhii Kovbasenko ◽  
Andriy Holyk ◽  
Serhii Hutarevych
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
Environmental Performance ◽  
Energy Performance ◽  
Dual Fuel ◽  
Fuel System ◽  
Compressed Natural Gas ◽  
Diesel Vehicles ◽  
Diesel Cycle ◽  
The Mathematical Model

The features of an advanced mathematical model of motion of a truck with a diesel engine operating on the diesel and diesel gas cycles are presented in the article. As a result of calculations using the mathematical model, a decrease in total mass emissions as a result of carbon monoxide emissions is observed due to a decrease in emissions of nitrogen oxides and emissions of soot in the diesel gas cycle compared to the diesel cycle. The mathematical model of a motion of a truck on a city driving cycle according to GOST 20306-90 allows to study the fuel-economic, environmental and energy indicators of a diesel and diesel gas vehicle. The results of the calculations on the mathematical model will make it possible to conclude on the feasibility of converting diesel vehicles to using compressed natural gas. Object of the study – the fuel-economic, environmental and energy performance diesel engine that runs on dual fuel system using CNG. Purpose of the study – study of changes in fuel, economic, environmental and energy performance of vehicles with diesel engines operating on diesel and diesel gas cycles, according to urban driving cycle modes. Method of the study – calculations on a mathematical model and comparison of results with road tests. Bench and road tests, results of calculations on the mathematical model of motion of a truck with diesel, working on diesel and diesel gas cycles, show the improvement of environmental performance of diesel vehicles during the converting to compressed natural gas in operation. Improvement of environmental performance is obtained mainly through the reduction of soot emissions and nitrogen oxides emissions from diesel gas cycle operations compared to diesel cycle operations. The results of the article can be used to further develop dual fuel system using CNG. Keywords: diesel engine, diesel gas engine, CNG

Glycemia monitoring

1998 ◽  
Vol 2 ◽  
pp. 23-30
Author(s):  
Igor Basov ◽  
Donatas Švitra
Keyword(s):  
Diabetes Mellitus ◽  
Mathematical Model ◽  
Numerical Methods ◽  
Differential Equations ◽  
Blood Sugar ◽  
Self Regulation ◽  
Physiological System ◽  
Non Linear ◽  
The Mathematical Model

Here a system of two non-linear difference-differential equations, which is mathematical model of self-regulation of the sugar level in blood, is investigated. The analysis carried out by qualitative and numerical methods allows us to conclude that the mathematical model explains the functioning of the physiological system "insulin-blood sugar" in both normal and pathological cases, i.e. diabetes mellitus and hyperinsulinism.

Mathematical Models of Papermaking

2001 ◽  
Vol 6 (1) ◽  
pp. 9-19 ◽  
Author(s):  
A. Buikis ◽  
J. Cepitis ◽  
H. Kalis ◽  
A. Reinfelds ◽  
A. Ancitis ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Initial Value Problems ◽  
Moisture Transfer ◽  
Bound Water ◽  
Drying Process ◽  
Initial Value ◽  
First Order ◽  
Heat And Moisture ◽  
The Mathematical Model ◽  
The Web

The mathematical model of wood drying based on detailed transport phenomena considering both heat and moisture transfer have been offered in article. The adjustment of this model to the drying process of papermaking is carried out for the range of moisture content corresponding to the period of drying in which vapour movement and bound water diffusion in the web are possible. By averaging as the desired models are obtained sequence of the initial value problems for systems of two nonlinear first order ordinary differential equations. 

The mathematical modelling of corrosion in hot dip galvanized steel reinforced concrete

2011 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
A. Hegyi ◽  
H. Vermeşan ◽  
V. Rus
Keyword(s):  
Mathematical Model ◽  
Reinforced Concrete ◽  
Numerical Model ◽  
Equation System ◽  
Galvanized Steel ◽  
Steel Reinforced Concrete ◽  
Numeric Model ◽  
Physical And Mathematical Models ◽  
Physical Phenomena ◽  
The Mathematical Model

Abstract In this paper we wish to present the numerical model elaborated in order to simulate some physical phenomena that influence the general deterioration of steel, whether hot dip galvanized or not, in reinforced concrete. We describe the physical and mathematical models, establishing the corresponding equation system, the initial and boundary conditions. We have also presented the numeric model associated to the mathematical model and the numeric methods of discretization and solution of the differential equations system that describes the mathematical model.

Sign in / Sign up

Export Citation Format

Share Document