Dynamics of a Damping Device Based on Ishlinsky Material

2019 ◽  
Vol 20 (2) ◽  
pp. 106-113 ◽  
Author(s):  
M. E. Semenov ◽  
M. G. Matveev ◽  
P. A. Meleshenko ◽  
A. M. Solovyov
Keyword(s):  
Mathematical Model ◽  
High Efficiency ◽  
Resonance Region ◽  
External Source ◽  
Weak Efficiency ◽  
Viscous Damper ◽  
Force Transmission ◽  
Hysteretic Damper ◽  
Hysteretic Nonlinearity ◽  
The Mathematical Model

In present paper we consider the damping properties of the oscillating system with hysteretic nature. The mathematical model of considered system is based on the operator approach for the hysteretic nonlinearity on the example of Ishlinsky material. Such a converter is a continual analogue of the set of stops connected in parallel. In the frame of the paper we compare the various approaches to modeling of damping systems. Namely, together with the hysteretic damper we consider the so-called nonlinear viscous damper which is a generalization of a standard linear damper with dependence on the velocity. The mathematical model of the considered system is formulated in terms of second order ordinary differential equation with hysteretic nonlinearity (namely, the operator-type nonlinearity). In comparison with the phenomenological models of hysteresis (such as Bouc-Wen model) that are often used in the modeling, the Ishlinsky model allows to " feel" the hysteretic nature of the material on the physical level. The major result of the presented paper is the comparison both the hysteretic and viscous (including the linear and nonlinear cases) dampers. Such a comparison is made in terms of transmission functions that reflect the "efficiency" of suppression of the external perturbations by the force transmission from an external source to the load. The results of numerical simulations showed the high efficiency of hysteretic damper both in and outside the resonance region (at the same time it is well known that the linear viscous damper has a weak efficiency outside the resonance region). The disadvantage of the hysteretic damper lies in the fact that its ability to dump the relative motion of the system under external forces is insignificantly reduced outside the resonance region.

Regenerative Gas Turbines With Divided Expansion

2004 ◽  
Author(s):  
Brian Elmegaard ◽  
Bjo̸rn Qvale
Keyword(s):  
Mathematical Model ◽  
Gas Turbines ◽  
High Efficiency ◽  
Limited Range ◽  
Simulation Program ◽  
Operating Parameters ◽  
Gas Generator ◽  
Extensive Simulation ◽  
Power Turbine ◽  
The Mathematical Model

Recuperated gas turbines are currently drawing an increased attention due to the recent commercialization of micro gas turbines with recuperation. This system may reach a high efficiency even for the small units of less than 100kW. In order to improve the economics of the plants, ways to improve their efficiency are always of interest. Recently, two independent studies have proposed recuperated gas turbines to be configured with the turbine expansion divided, in order to obtain higher efficiency. The idea is to operate the system with a gas generator and a power turbine, and use the gas from the gas generator part for recuperation ahead of the expansion in the power turbine. The present study is more complete than the predecessors in that the ranges of the parameters have been extended and the mathematical model is more realistic using an extensive simulation program. It is confirmed that the proposed divided expansion can be advantageous under certain circumstances. But, in order for todays micro gas turbines to be competitive, the thermodynamic efficiencies will have to be rather high. This requires that all component efficiencies including the recuperator effectiveness will have to be high. The advantages of the divided expansion manifest themselves over a rather limited range of the operating parameters, that lies outside the range required to make modern micro turbines economically competitive.

Bearingless Permanent Magnet Synchronous Motor using Independent Control

2015 ◽  
Vol 6 (2) ◽  
pp. 233
Author(s):  
Normaisharah Mamat ◽  
Kasrul Abdul Karim ◽  
Zulkiflie Ibrahim ◽  
Tole Sutikno ◽  
Siti Azura Ahmad Tarusan ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Speed ◽  
High Performance ◽  
High Efficiency ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Magnetic Bearing ◽  
Force Model ◽  
The Mathematical Model

Bearingless permanent magnet synchronous motor (BPMSM) combines the characteristic of the conventional permanent magent synchronous motor and magnetic bearing in one electric motor. BPMSM is a kind of high performance motor due to having both advantages of PMSM and magnetic bearing with simple structure, high efficiency, and reasonable cost. The research on BPMSM is to design and analyse BPMSM by using Maxwell 2-Dimensional of ANSYS Finite Element Method (FEM). Independent suspension force model and bearingless PMSM model are developed by using the method of suspension force. Then, the mathematical model of electromagnetic torque and radial suspension force has been developed by using Matlab/Simulink. The relation between force, current, distance and other parameter are determined. This research covered the principle of suspension force, the mathematical model, FEM analysis and digital control system of bearingless PMSM. This kind of motor is widely used in high speed application such as compressors, pumps and turbines.

scholarly journals Mathematical Modelling of a Hybrid Micro-Cogeneration Group Based on a Four Stroke Diesel Engine

2014 ◽  
Vol 10 (2) ◽  
pp. 31-36
Author(s):  
Valentin Apostol ◽  
Tudor Prisecaru ◽  
Cristian Petcu ◽  
Alexandru Dobrovicescu ◽  
Mălina Prisecaru ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
High Efficiency ◽  
Combustion Engine ◽  
Irreversible Processes ◽  
Future Developments ◽  
Exergetic Analysis ◽  
The Mathematical Model ◽  
Very High ◽  
Research Grant

Abstract The paper presents a part of the work conducted in the first stage of a Research Grant called ”Hybrid micro-cogeneration group of high efficiency equipped with an electronically assisted ORC” acronym GRUCOHYB. The hybrid micro-cogeneration group is equipped with a four stroke Diesel engine having a maximum power of 40 kW. A mathematical model of the internal combustion engine is presented. The mathematical model is developed based on the Laws of Thermodynamics and takes into account the real, irreversible processes. Based on the mathematical model a computation program was developed. The results obtained were compared with those provided by the Diesel engine manufacturer. Results show a very high correlation between the manufacturer’s data and the simulation results for an engine running at 100% load. Future developments could involve using an exergetic analysis to show the ability of the ORC to generate electricity from recovered heat

scholarly journals HIGH EFFICIENCY PNEUMATIC SYSTEMS COMPRESSORS HYDRODYNAMICS AND TERMODYNAMICS PROCESS RESEARCH / DIDELIO NAŠUMO PNEUMATINĖS SISTEMOS KOMPRESORIŲ HIDRODINAMINIŲ IR TERMODINAMINIŲ PROCESŲ TYRIMAS

2016 ◽  
Vol 8 (5) ◽  
pp. 514-518
Author(s):  
Paulius Bogdevičius ◽  
Bronislovas Spruogis ◽  
Marijonas Bogdevičius
Keyword(s):  
Mathematical Model ◽  
High Efficiency ◽  
Piston Compressor ◽  
Process Research ◽  
Kinematic Parameters ◽  
Mathematical Experiment ◽  
Cylinder Piston ◽  
The Mathematical Model ◽  
Asynchronous Electric Motor ◽  
Thermodynamic Processes

The paper analyzes pneumatic system, which consists of three piston compressors, pipes and reciever. Designed two cylinder piston compressor with an asynchronous electric motor mathematical model. In the mathematical model has been estimated rod mechanism geometry and kinematic parameters also hudrodynamics and thermodynamic processes going in the cylinders. Also there were made mathematical experiment and presented the results of it. Nagrinėjama pneumatinė sistema, sudaryta iš trijų stūmoklinių kompresorių, vamzdžių ir resiverio. Sukurtas dviejų cilindrų stūmoklinio kompresoriaus su asinchroniniu elektriniu varikliu matematinis modelis, kuriuo įvertinama: švaistiklinio mechanizmo geometrija ir kinematiniai parametrai, cilindruose vykstantys hidrodinaminiai ir termodinaminiai procesai. Atliktas nagrinėjamos sistemos matematinis eksperimentas, pateikti tyrimo rezultatai.

Studies on Epitrochoid Gear for Cycloid Drives

2003 ◽  
Vol 19 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Shinn-Liang Chang
Keyword(s):  
Mathematical Model ◽  
Differential Geometry ◽  
Service Life ◽  
High Efficiency ◽  
Gear Ratio ◽  
Low Noise ◽  
Force Transmission ◽  
Compact Size ◽  
Tooth Number ◽  
Computerized Simulation

ABSTRACTCycloid drives are widely used in the industries because of their excellent characteristics, namely, high gear ratio, smooth transmission, compact size, high efficiency, low noise and long service life. In this paper, a mathematical model of an epitrochoid gear for a cycloid drive with a small tooth number difference has been proposed. Computerized simulation of the generated epitrochoid gear has also been developed. In this paper, the pressure angle, which has an important role in the analysis of cycloid drives as it influences the direction and magnitude of force transmission in gears, is derived based on the theory of differential geometry. The rack cutter profile, which is the fundamental tooth profile of a hob cutter, which in turn is the main manufacturing process of epitrochoid gear, has been obtained based on the theory of gearing. It is anticipated that the results from this paper will be beneficial to the design, analysis and manufacture of cycloid drives.

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.

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