scholarly journals Physical-mathematical model of ground adhesion on the surface of the excavating parts of earthmoving machines

2021 ◽  
Vol 7 (4) ◽  
pp. 381-388
Author(s):  
L.A. Sladkova ◽  
◽  
P.A. Grigorev ◽  
Keyword(s):  
Mathematical Model ◽  
Probability Theory ◽  
Physical Model ◽  
Classical Theory ◽  
Theoretical Studies ◽  
Soil Particles ◽  
Earthmoving Machines

A large number of domestic and foreign scientists were engaged in the wear of the surfaces of the excavating parts of earthmoving machines during their interaction with the ground, as well as the problem of the adhesion of soils on the surface of the working excavating parts of machines and methods of struggle. It is known that the classical theory of digging is based on empirical dependencies obtained experimentally. They allow, basically, to reveal the essence of the process of dredging, but they differ from each other, both in their description and in the number of results. In this article, the authors propose, on the basis of probability theory, theoretical studies of the process of dredging and the interaction of the excavating part with the soil. The authors of previous studies confirm the obtained results. The developed physical model of the interaction of soil particles with the surface of the excavating part during adhesion allows us to reveal the physical cause of the process of wear of the surface of the excavating parts.

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.

Theoretical studies on capillary microviscometry of skeletal muscle actin

1983 ◽  
Vol 3 (2) ◽  
pp. 195-206
Author(s):  
Mitsuhiko Masuhara ◽  
Hiroyuki Yokoyama ◽  
Noriyuki Tatsumi
Keyword(s):  
Mathematical Model ◽  
Skeletal Muscle ◽  
Large Volume ◽  
Theoretical Studies ◽  
Muscle Actin

For improving Ostwald's viscometry, which is time-consuming and requires a relatively large volume of specimen to determine viscosity, we developed a capillary microviscometric method with an appropriate mathematical model, and have compared this method with Ostwald's method.

scholarly journals Economic Analysis of Solar Refrigeration and Desalination System

2019 ◽  
Vol 118 ◽  
pp. 02021
Author(s):  
Xiaoman Zhang ◽  
Qin Shen ◽  
Shijun Zhu
Keyword(s):  
Mathematical Model ◽  
Economic Analysis ◽  
Physical Model ◽  
Energy Supply ◽  
Recovery Period ◽  
Heat Consumption ◽  
Refrigeration System ◽  
Generation System ◽  
Refrigeration Capacity ◽  
Solar Refrigeration

The physical model and mathematical model of solar refrigeration and desalination co-generation system were established. The performance and economy of the system were analyzed by changing the three variables of refrigeration capacity, seawater desalination effects number and three different cities. The results show that increasing refrigeration capacity is conducive to improving freshwater production and increasing freshwater efficiency, but more auxiliary heat consumption is needed, the comprehensive effect is to shorten the recovery period. Increasing desalination efficiency is conducive to increasing freshwater production and freshwater efficiency, and the auxiliary heat consumption remains unchanged. The comprehensive effect is to shorten the recovery period. Solar energy is the main energy needed in the co-generation system of the three cities, and Shenzhen has the largest proportion of energy supply, which reaches 67.8%. Compared with the solar refrigeration system, the recovery period of the co-generation system can bu shortened by 18.1%.

scholarly journals Bifurcation phenomena and statistical regularities in dynamics of forced impacting oscillator

2019 ◽  
Vol 98 (3) ◽  
pp. 1795-1806 ◽  
Author(s):  
Sergii Skurativskyi ◽  
Grzegorz Kudra ◽  
Krzysztof Witkowski ◽  
Jan Awrejcewicz
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Physical Model ◽  
Dry Friction ◽  
Stepper Motor ◽  
Nonlinear Phenomenon ◽  
Hertz Contact ◽  
Bifurcation Phenomena ◽  
Statistical Regularities ◽  
The Mathematical Model

Abstract The paper is devoted to the study of harmonically forced impacting oscillator. The physical model for oscillator is a cart on a guide connected to the support with springs and excited by the stepper motor. The support also is provided with limiter of motion. The mathematical model for this system is defined with the second-order piecewise smooth differential equation. Model’s nonlinearity is connected with the incorporation of dry friction and generalized Hertz contact law. Analyzing the classical Poincare sections and inter-impact sequences obtained experimentally and numerically, the bifurcations and statistical properties of periodic, multi-periodic, and chaotic regimes were examined. The development of impact-adding regime as a new nonlinear phenomenon when the forcing frequency varies was observed.

Mathematical and Physical Modeling of Three-Phase Gas-Stirred Ladles

2016 ◽  
Vol 1812 ◽  
pp. 29-34
Author(s):  
Juan A. López ◽  
Marco A. Ramírez-Argáez ◽  
Adrián M. Amaro-Villeda ◽  
Carlos González
Keyword(s):  
Mathematical Model ◽  
Physical Model ◽  
Stokes Equations ◽  
Steel Slag ◽  
Flow Patterns ◽  
Navier Stokes ◽  
Steel Ladle ◽  
Phase System ◽  
Navier Stokes Equations ◽  
Three Phase

ABSTRACTA very realistic 1:17 scale physical model of a 140-ton gas-stirred industrial steel ladle was used to evaluate flow patterns measured by Particle Image Velocimetry (PIV), considering a three-phase system (air-water-oil) to simulate the argon-steel-slag system and to quantify the effect of the slag layer on the flow patterns. The flow patterns were evaluated for a single injector located at the center of the ladle bottom with a gas flow rate of 2.85 l/min, with the presence of a slag phase with a thickness of 0.0066 m. The experimental results obtained in this work are in excellent agreement with the trends reported in the literature for these gas-stirred ladles. Additionally, a mathematical model was developed in a 2D gas-stirred ladle considering the three-phase system built in the physical model. The model was based on the Eulerian approach in which the continuity and the Navier Stokes equations are solved for each phase. Therefore, there were three continuity and six Navier-Stokes equations in the system. Additionally, turbulence in the ladle was computed by using the standard k-epsilon turbulent model. The agreement between numerical simulations and experiments was excellent with respect to velocity fields and turbulent structure, which sets the basis for future works on process analysis with the developed mathematical model, since there are only a few three-phase models reported so far in the literature to predict fluid dynamics in gas-stirred steel ladles.

scholarly journals A continuum hyperelastic model for auxetic materials

2014 ◽  
Vol 470 (2163) ◽  
pp. 20130691 ◽  
Author(s):  
J. Ciambella ◽  
G. Saccomandi
Keyword(s):  
Mathematical Model ◽  
Constitutive Equation ◽  
Nonlinear Elasticity ◽  
Classical Theory ◽  
Simple Mathematical Model ◽  
Material Behaviour ◽  
Poisson Function ◽  
Auxetic Materials ◽  
Hyperelastic Model ◽  
Constitutive Parameters

We propose a simple mathematical model to describe isotropic auxetic materials in the framework of the classical theory of nonlinear elasticity. The model is derived from the Blatz–Ko constitutive equation for compressible foams and makes use of a non-monotonic Poisson function. An application to the modelling of auxetic foams is considered and it is shown that the material behaviour is adequately described with only three constitutive parameters.

scholarly journals MATHEMATICAL MODEL OF SPATIAL OSCILLATIONS OF A RAILWAY FOUR-AXLE AUTONOMOUS TRACTION MODULE

2021 ◽  
pp. 55-68
Author(s):  
František Bures
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Mechanical System ◽  
Traffic Safety ◽  
Equations Of Motion ◽  
Rigid Bodies ◽  
Railway Track ◽  
Theoretical Studies ◽  
System Of Differential Equations ◽  
Spatial Oscillations

A description of the original mathematical model of spatial oscillations of a four-axle autonomous traction module during its movement along straight and curved sections of the railway track is proposed. In this case, the design of a four-axle autonomous traction module is presented as a complex mechanical system, and the track is considered as an elastic-viscous inertial system. The equations of motion were compiled using the Lagrange method of the ІІ kind. For each of the solids, the kinetic energy is determined by the Koenig theorem. The potential energy component is obtained by the Clapeyron theorem, as the sum of the energies accumulated in the elastic elements of the system during their deformations. The dissipative energy was also taken into account when compiling the equations of motion. Generalized forces that have no potential, in this case, include the forces of interaction between wheels and rails, which are determined using the creep hypothesis. It is important to note that the model takes into account the forces in the bonds between the bodies of the system and the spatial displacements of the rigid bodies of the mechanical system, taking into account possible restrictions. Moreover, the mathematical model developed by the author is a system of differential equations of the 100th order. This mathematical model is the base for further theoretical studies of the dynamics of railway four-axle autonomous traction modules in single motion or when moving as part of a train. To solve the resulting system of differential equations, the author develops special software that allows for complex theoretical studies of spatial oscillations of a four-axle autonomous tractionmodule to determine the indicators of its dynamic loading and traffic safety. 

scholarly journals DEVELOPMENT OF PHYSICAL MODEL VEHICLE WITH REMOTIONAL CONTROL FOR EXPERIMENTAL STUDIES OF VEHICLE PROPERTIES

2020 ◽  
Vol 1 (46) ◽  
pp. 341-352
Author(s):  
Timkov O ◽  
◽  
Yashchenko D ◽  
Keyword(s):  
Mathematical Model ◽  
Experimental Study ◽  
Remote Control ◽  
Physical Model ◽  
Large Scale ◽  
Experimental Studies ◽  
Scale Model ◽  
Recording Equipment ◽  
Control Equipment ◽  
The Future

The article is devoted to the development of the physical model of the vehicle, the equipment of the measuring, recording and remote control equipment for the experimental study of the properties vehicles. The construction of the physical model and the used electronic modules is described in detail, references are given to the application libraries and the code of the first part of the program for remote control. In the future, it is planned to develop a mathematical model of the movement of a passenger vehicle and to check its adequacy in conducting experimental studies on maneuverability on a physical model. The aim of the article is developed the physical model of the vehicle, equipped with measuring, recording and remote control equipment, for the experimental study of the properties of vehicle. Materials and research methods: development and designing (experimental research of properties of vehicles on the physical model); remote control; wheeled controlled module. The self-propelled large-scale model of the vehicle, reproducing a passenger car of the category M1, with a controlled wheelbase and a rear drive axle, has been developed. The model is equipped with the necessary measuring and recording equipment and remote control equipment. The software of the model allows you to implement both control manual and the given algorithm. In the future, it is planned to develop a mathematical model of the vehicle motion and to check its adequacy on the developed physical model. The obtained results will allow to improve not only the mathematical model, but also the experimental physical model and proceed further to the study of the properties of hybrid road trains with an active trailer link. KEY WORDS: VEHICLE, PHYSICAL MODEL, EXPERIMENT, STUDY, MODULE, MEMORY CARD, ACCELEROMETER, PROGRAM.

Mathematical model of oil-containing water purification process in the volume of granulated media

2018 ◽  
Vol 233 (3) ◽  
pp. 879-885
Author(s):  
Valeriy Ivanovich Istomin ◽  
Elena Stanislavovna Solodova ◽  
Viktoria Valer’evna Khlebnikova
Keyword(s):  
Mathematical Model ◽  
Physical Model ◽  
Water Purification ◽  
Theoretical Research ◽  
Purification Process ◽  
Operational Parameters ◽  
Filtering Element ◽  
The Mathematical Model ◽  
First Time ◽  
Further Development

A mathematical model of oil-containing water purification process in the volume of granulated media is developed. On the basis of this model, the purifying ability of filtering unit with granulated coalescing media, which regenerates filtering media in the mode of pseudo liquefaction of granule without disassembling and replacement of filtering element, is studied. In the process of theoretical research, the physical model of oil-containing water purification process in the volume of granulated coalescing media is elaborated. The consistent patterns of the analysed process have gained further development. Due to these patterns, the factors which determine the effectiveneness of purification are established. After realization of the experiment plan for the first time, the mathematical model of a ship’s oil-containing water purification process in the volume of granulated media on the basis of the regression equation has been received. This model allows to calculate the rational constructive and operational parameters of the plant with granulated filter elements.

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