scholarly journals Electromagnetic analysis of single/multiple grounding rods

2018 ◽  
Vol 31 (3) ◽  
pp. 487-500
Author(s):  
Vesna Arnautovski-Toseva ◽  
Leonid Grcev
Keyword(s):  
Mathematical Model ◽  
Integral Equation ◽  
Current Density ◽  
Wide Frequency Range ◽  
Electromagnetic Analysis ◽  
Mixed Potential ◽  
Electromagnetic Modeling ◽  
Frequency Range ◽  
The Mathematical Model

This paper presents electromagnetic modeling of multiple driven grounding rods in homogeneous/two-layer soil. The mathematical model is formulated by mixed potential integral equation (MPIE) on the basis of Sommerfield integrals. Several configurations of multiple driven rods located in homogeneous or two-layer soil are analyzed. The authors are focused on the calculation of the current density along the rods in wide frequency range from 100Hz to 1MHz.

Developing of an Active Hydraulic Bushing for Multi-Displacement Engines

2006 ◽  
Author(s):  
S. Arzanpour ◽  
M. F. Golnaraghi
Keyword(s):  
Mathematical Model ◽  
Research Effort ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Feedback Signal ◽  
Frequency Range ◽  
Engine Mount ◽  
Isolation Requirements ◽  
Stiffness And Damping ◽  
The Mathematical Model

This paper outlines the development of an active hydraulic bushing system for the Multi Displacement System (MDS) Engine isolation problems. The prior art research effort on engine mounts and bushings has so far focused on the improvement of the mount dynamic stiffness properties. The optimum dynamic stiffness and damping of the engine bushings is both frequency and amplitude dependent. While these systems are available commercially, they have many limitations, particularly for new vehicle models and new engine generations such as MDS engines. A suitable isolator for an MDS engine should be half as stiff in the operating frequency range of the engine (5-70 Hz) in MDS mode, while showing the same performance as conventional hydraulic bushings in normal engine operations. Passive hydraulic bushings are not capable of meeting the isolation requirements discussed for the MDS engines because they are not adjustable. There are different parameters which contribute to the dynamic stiffness response of a hydraulic bushing. Some of those parameters are defined by passive components such as rubber stiffness and damping. However, other parameters such as the pressure inside the bushing can be altered actively. The mathematical model of a conventional hydraulic bushing is given in this paper. The model suggests that the pressure inside the bushing has a significant role in the dynamic stiffness response of the bushing. As a result, an additional pumping chamber is introduced as a solution. The pump is utilized to adjust the pressure inside the bushing based on the engine excitation frequency. This pump can be driven by proper actuators which can produce pressure differences in the frequency range of interest. The mechanical and mathematical model of such a system is derived using a simplified linear model. This technique enables the engine mount to adjust to the dynamic stiffness characteristics by applying a feedback signal to the actuator. The feedback signal to the actuator is also obtained using the mathematical model for many required cases yet adjustable for others. The response of the system is discussed in frequency domains. The simulation results prove that the additional pumping chamber can effectively be used to control the stiffness of the conventional hydraulic bushings.

scholarly journals Investigation of Electromagnetic Influence on the Liquid Heart of Aluminium Ingots at Continuous Casting in a Direct Chill Mold

2019 ◽  
pp. 952-961
Author(s):  
Mikhail V. Pervukhin ◽  
Mikhail Y. Kuchinskii ◽  
Sergei P. Timofeev
Keyword(s):  
Mathematical Model ◽  
Continuous Casting ◽  
Physical Modeling ◽  
Direct Chill ◽  
Power Line ◽  
Frequency Range ◽  
Electromagnetic Process ◽  
Chill Mold ◽  
Mathematical And Physical Modeling ◽  
The Mathematical Model

The mathematical model of system "inductor-ingot" for investigation electromagnetic process at the continuous casting of aluminum ingots in a direct chill mold is considered in this article. Calculation at various parameters of a power line is made, electromechanical characteristics of stirrer are found. The frequency range at which electromagnetic influence of an inductor on a liquid heart of an ingot is most effective is established. The results of mathematical and physical modeling which have shown reliability of mathematical model are compared

scholarly journals TO THE QUESTION OF OPTIMISING THE DYNAMIC CHARACTERISTICS OF A VIBRATIONAL TREE UPROOTING MACHINE

2018 ◽  
Vol 45 (2) ◽  
pp. 149-157
Author(s):  
A. R. Mikhitarov ◽  
V. L. Savich ◽  
V. K. Khegai
Keyword(s):  
Mathematical Model ◽  
Root System ◽  
Dynamic Characteristics ◽  
Mutual Influence ◽  
Frequency Characteristics ◽  
Frequency Range ◽  
System A ◽  
Forest Sites ◽  
Tree Uprooting ◽  
The Mathematical Model

Objectives Following logging operations, tree stumps remain in the site of the former forest.While these may be uprooted by special machines in the course of forestry operations, the use of heavy forestry machines operated repeatedly on the forest sites not only lead to soil erosion, but also to considerable financial expense. Consequently, the development of machines combining cutting (logging) and uprooting operations – that is, uprooting the trees along with their roots – are of a great interest. As research has shown, the main disadvantages of the use of such technology by “conventional” logging or forestry machines are their excessive loading and energy intensity. The aim of the research is to investigate means of eliminating these drawbacks by using vibration.Methods The article deals with theproblem of ensuring the effectiveness of the vibration application – in particular, torsional vibrations, used to stub trees together with their roots. To solve this problem, a mathematical model of the “machine-tree-soil-root system” system was developed, which takes into account the mutual influence of the dynamic characteristics of the machine’s technological equipment and tree and soil-root system, which allows a rational (optimal) frequency range of vibration equipment to be selected by analysing the amplitude-frequency characteristics of a given system. To analyse the amplitude-frequency characteristics of a mechanical system, the Euler-Lagrange equationswere used.Results Based on the mathematical model of the “machine-tree-soil-root system (SRS)” system and an analysis of the amplitude-frequency characteristics of a given system, a rational range of vibration frequencies was determined. As shown by analysis, the work of vibrational equipment in a given frequency range can significantly reduce the dynamic loading of the machine and at the same time create appropriate conditions for the effective destruction of the soil-root system.Conclusion The proposed method allows the rational values of the frequency characteristic of vibration equipment for each calculated tree to be found depending on the soil type and the basic machine.

LOW-FREQUENCY IMPEDANCE OF ANISOTROPIC ENGINEERING DESIGN

Akustika ◽  
2021 ◽  
pp. 262
Author(s):  
Sergey A. Rykov ◽  
Irina Kudryavtseva ◽  
Sergey V. Rykov
Keyword(s):  
Mathematical Model ◽  
Engineering Design ◽  
Experimental Research ◽  
Great Influence ◽  
Low Frequency ◽  
Inhomogeneous Distribution ◽  
Anisotropic Structure ◽  
Frequency Range ◽  
Anisotropic Structures ◽  
The Mathematical Model

The results of theoretical and experimental research of the impedance of an anisotropic structure in the low frequency range are presented. It is shown that taking into account the inhomogeneous distribution of mass along the length of the structure has a great influence on the value of the impedance of an anisotropic structure. Based on the results obtained in the mathematical model, expressions are proposed for calculating the impedances of anisotropic structures in the low frequency range.

scholarly journals CONSTRUCTING A MODEL OF VIBROSEIS SIGNAL COMPLICATED BY HARMONICS

2020 ◽  
Vol 1 (1) ◽  
pp. 72-83 ◽  
Author(s):  
M. S. Denisov ◽  
A. A. Egorov
Keyword(s):  
Mathematical Model ◽  
Basis Function ◽  
Harmonic Distortion ◽  
Frequency Range ◽  
Frequency Dependent ◽  
Function Decomposition ◽  
Starting Point ◽  
Processing Algorithms ◽  
The Mathematical Model ◽  
Basis Decomposition

We solve the problem of constructing the mathematical model of a vibroseis signal distorted by harmonics. Basis function decomposition is used for the approximation. The basis decomposition coefficients are frequency-dependent, i. e. filters are applied instead of multipliers. The resulting model will be the starting point for further research aimed at developing processing algorithms for the suppression of harmonic distortion, or for utilizing the harmonics to extend the frequency range of the signal.

A Study on Boundary Integral Equation for Acoustic Radiation From Axisymmetric Bodies

2000 ◽  
Author(s):  
G. R. Liu ◽  
C. Cai ◽  
H. Zheng ◽  
K. Y. Lam
Keyword(s):  
Integral Equation ◽  
Point Source ◽  
Boundary Integral Equation ◽  
Singular Integral ◽  
Acoustic Radiation ◽  
Wide Frequency Range ◽  
Boundary Integral ◽  
Frequency Range ◽  
Spherical Structure ◽  
Axisymmetric Bodies

Abstract A technique named the RDT (Reproduction of Diagonal Terms) is presented to improve the accuracy and the reliability of Conventional Boundary Integral Equation (CBIE) applied to acoustic radiation from axisymmetric bodies. In CBIE, the higher order singular integral is eliminated by placing a fabricated point source inside the boundary. Numerical results for a spherical structure show that the accuracy is obviously raised up to 10 times at higher frequency upon use of the RDT method, and the CHIEF and improved Burton & Miller methods can work with the technique presented in a wide frequency range with better accuracy.

scholarly journals On the generalized fractional snap boundary problems via G-Caputo operators: existence and stability analysis

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohammad Esmael Samei ◽  
Mohammed M. Matar ◽  
Sina Etemad ◽  
Shahram Rezapour
Keyword(s):  
Mathematical Model ◽  
Integral Equation ◽  
Fixed Point ◽  
Stability Analysis ◽  
Numerical Simulations ◽  
Boundary Problems ◽  
Existence And Stability ◽  
Existence Criterion ◽  
The Mathematical Model ◽  
Fixed Point Techniques

AbstractThis research is conducted for studying some qualitative specifications of solution to a generalized fractional structure of the standard snap boundary problem. We first rewrite the mathematical model of the extended fractional snap problem by means of the $\mathbb{G}$ G -operators. After finding its equivalent solution as a form of the integral equation, we establish the existence criterion of this reformulated model with respect to some known fixed point techniques. Then we analyze its stability and further investigate the inclusion version of the problem with the help of some special contractions. We present numerical simulations for solutions of several examples regarding the fractional $\mathbb{G}$ G -snap system in different structures including the Caputo, Caputo–Hadamard, and Katugampola operators of different orders.

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.

Sign in / Sign up

Export Citation Format

Share Document