scholarly journals Innovative electrical engineering developed for the transport industry by the Emperor Alexander I Petersburg State Transport University

2021 ◽  
Vol 2021 (4) ◽  
pp. 87-103
Author(s):  
Konstantin K. KIM ◽  
◽  
Aleksandr Yu. PANYCHEV ◽  
Keyword(s):  
High Speed ◽  
Practical Importance ◽  
Electrical Energy ◽  
Solid Lubricants ◽  
Contact Network ◽  
Contactless Method ◽  
Increase Energy Efficiency ◽  
Plasma Device ◽  
Transport Industry ◽  
Electromechanical Converter

Objective: To familiarize the general scientific community with the latest electrotechnical innovative developments for the transport industry, carried out by the scientists of the Emperor Alexander I Petersburg State Transport University in the period from 2000 to 2021. Methods: We used the methods of calculation of electromagnetic fields and circuits, mathematical analysis, mathematical physics and numerical methods in the development of the described devices and systems. Results: 101 We developed a pipeline high-speed magnetolevitation transport system with vehicle movement in a rarefied atmosphere, a series of pantograph pantographs for heavy-loaded and high-speed trains using solid lubricants and a contactless method of transmitting electrical energy, a plasma device for fine cleaning of circuit boards for microcircuits, a device for creating a comfortable climate in office premises, electrohydroimpulse installations designed for loosening frozen coal in gondola cars in winter, shock tests of wagons, escalators and travalators using linear electric motors, high-speed electric switches-breakers, heat generators based on an electromechanical converter with the functions of a heater and pump, a wagon generator with a forced excitation system, a pulse voltage generator, allowing to measure the pulse resistance of the grounding conductors of the contact network supports, a complex of installations for various purposes using ozone technologies, a system for laser monitoring of the integrity of tanks, a device for diagnosing the degree of corrosion of the fittings of contact supports, an electrohydroimpulse installation for impact welding, treatment plants, technology for recycling car tires, security systems of the main trackbed. Practical importance: The use of the described developments will increase energy efficiency, energy saving and safety of production processes in transport

scholarly journals Droplet impact onto a spring-supported plate: analysis and simulations

2021 ◽  
Vol 128 (1) ◽  
Author(s):  
Michael J. Negus ◽  
Matthew R. Moore ◽  
James M. Oliver ◽  
Radu Cimpeanu
Keyword(s):  
High Speed ◽  
Flexible Substrate ◽  
Practical Importance ◽  
Hybrid Approach ◽  
Hydrodynamic Pressure ◽  
Analytical Framework ◽  
Canonical System ◽  
Linear Process ◽  
Plate Motion ◽  
The Impact

AbstractThe high-speed impact of a droplet onto a flexible substrate is a highly non-linear process of practical importance, which poses formidable modelling challenges in the context of fluid–structure interaction. We present two approaches aimed at investigating the canonical system of a droplet impacting onto a rigid plate supported by a spring and a dashpot: matched asymptotic expansions and direct numerical simulation (DNS). In the former, we derive a generalisation of inviscid Wagner theory to approximate the flow behaviour during the early stages of the impact. In the latter, we perform detailed DNS designed to validate the analytical framework, as well as provide insight into later times beyond the reach of the proposed analytical model. Drawing from both methods, we observe the strong influence that the mass of the plate, resistance of the dashpot, and stiffness of the spring have on the motion of the solid, which undergo forced damped oscillations. Furthermore, we examine how the plate motion affects the dynamics of the droplet, predominantly through altering its internal hydrodynamic pressure distribution. We build on the interplay between these techniques, demonstrating that a hybrid approach leads to improved model and computational development, as well as result interpretation, across multiple length and time scales.

Comparative Evaluation of MoS2 and WS2 as Powder Lubricants in High Speed, Multi-Pad Journal Bearings

1999 ◽  
Vol 121 (3) ◽  
pp. 625-630 ◽  
Author(s):  
C. Fred Higgs ◽  
Crystal A. Heshmat ◽  
Hooshang Heshmat
Keyword(s):  
Comparative Evaluation ◽  
High Speed ◽  
Solid Lubricants ◽  
Extreme Environment ◽  
Journal Bearings ◽  
Lubricating Film ◽  
Constant Friction ◽  
Traction Coefficient ◽  
Limiting Value ◽  
Selection Of

As part of a program to develop solid/powder-lubricated journal bearings, a comparative evaluation has been performed to aid in determining whether MoS2 and WS2 powder are suitable lubricants for high-speed, extreme-environment multi-pad journal bearings. Plots of traction coefficients, friction, frictional power loss, and bearing pad temperature are presented as a means for comparing various powder lubricants. This paper primarily focuses on experiments carried out on a three-pad journal bearing and a disk-on-disk tribometer. Results showed that MoS2 traction curves resemble that of SAE 10 synthetic oil. Unlike liquid lubricants, powder films have a limiting shear strength property. Once the powder reaches this limiting value, the maximum traction coefficient is limited and the powder essentially shears along sliding walls. Experimental traction data shows evidence of this property in various powders. The thermal performance of the bearing was evaluated at speeds up to 30,000 rpm and loads up to 236 N. Although WS2 displayed constant friction coefficient and low temperature with increasing dimensionless load, MoS2 exhibited frictional behavior resembling that of a hydrodynamic lubricating film. In this paper, an attempt has been made to provide a criterion for the selection of solid lubricants for use in those tribosystems that may be operated in a high speed/load regime (i.e., high strain rates) as an alternative yard stick to conventional comparative approaches.

Some problems of assessing the dynamic crack resistance of structural steels

2021 ◽  
Vol 18 (3) ◽  
pp. 428-435
Author(s):  
Vladimir I. SMIRNOV ◽  
◽  
Tatiana A. KNOPOVA ◽  
Sergey S. MAYER ◽  
◽  
...  
Keyword(s):  
Crack Resistance ◽  
High Speed ◽  
Dynamic Testing ◽  
Practical Importance ◽  
Dynamic Strength ◽  
Structural Steels ◽  
Dynamic Crack ◽  
Unstable Fracture ◽  
Structural Elements ◽  
Limiting State

Objective: Solving the problem of determining the conditions for the onset and development of unstable fracture, which is extremely important for the development of methods for calculating the limiting states of structural elements, improving the dynamic testing schemes of materials and classifying steels according to their ability to resist fracture. Methods: Analytical methods for assessing the limiting state of structural elements are used. Results: A brief overview of the available test methods for structural steels for dynamic strength and crack resistance is given. The experience accumulated by domestic and foreign practices in testing steels for strength and crack resistance under high-speed loading is analyzed. The disadvantages of the existing methods for assessing the indicators of dynamic strength and resistance to brittle fracture are indicated. Practical importance: It is shown that along with the traditional methods for assessing strength based on safety factors, it is necessary to develop and apply new methods for assessing the limiting state of structural elements, including by the criteria of crack resistance

scholarly journals Novel analysis methods of dynamic properties for vehicle pantographs

2018 ◽  
Vol 180 ◽  
pp. 01005 ◽  
Author(s):  
Andrzej Wilk
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
High Speed ◽  
Dynamic Properties ◽  
Equations Of Motion ◽  
Computer Software ◽  
Fem Analysis ◽  
Electrical Energy ◽  
Modern Approach ◽  
Static And Dynamic Analysis

Transmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should take into account: mass distribution of particular parts, physical properties of used materials, kinematic joints character at mechanical nodes, nonlinear parameters of kinematic joints, defining different parametric waveforms of forces and torques, and numerical dynamic simulation coupled with FEM calculations. In this work methods for the formulation of the governing equations of motion are presented. Some of these methods are more suitable for automated computer implementation. The novel computer methods recommended for static and dynamic analysis of pantographs are presented. Possibilities of dynamic analysis using CAD and CAE computer software are described. Original results are also presented. Conclusions related to dynamic properties of pantographs are included. Chapter 2 presents the methods used for formulation of the equation of pantograph motion. Chapter 3 is devoted to modelling of forces in multibody systems. In chapter 4 the selected computer tools for dynamic analysis are described. Chapter 5 shows the possibility of FEM analysis coupled with dynamic simulation. In chapter 6 the summary of this work is presented.

scholarly journals Development of a method for estimating the effect of transformation of the normalized frequency mismatch function of a coherent bundle of radio pulses on the quality of radar frequency resolution

2021 ◽  
Vol 4 (4(112)) ◽  
pp. 13-22
Author(s):  
Serhii Yevseiev ◽  
Oksana Biesova ◽  
Dmytro Kyrychenko ◽  
Olena Lukashuk ◽  
Stanislav Milevskyi ◽  
...  
Keyword(s):  
High Speed ◽  
Practical Importance ◽  
Frequency Resolution ◽  
Phase Fluctuations ◽  
Twofold Increase ◽  
Normalized Frequency ◽  
Frequency Mismatch ◽  
Multiplicative Effect ◽  
Radar Frequency

The necessity of studying the influence of the transformation of the frequency mismatch function of a coherent bundle of radio pulses on the quality of solving the radar frequency resolution problem is substantiated. This solution determines the effectiveness of radar observation of high-speed and maneuvering individual and group aerodynamic objects. The method is based on explicit expressions for calculating the normalized frequency mismatch function of a coherent bundle of radio pulses, taking into account its transformation due to the radial motion of high-speed and maneuvering individual and group aerodynamic objects. The estimation of the potential frequency resolution of bundles with different numbers of radio pulses with typical parameters for a coherent pulse radar is carried out. Possible values of frequency resolution under the additive effect of uncorrelated internal noise of the radar receiver and the multiplicative effect of correlated phase fluctuations of the radar signal are estimated. With an insignificant multiplicative effect of correlated phase fluctuations, a twofold increase in the number of radio pulses in a bundle provides an improvement in the frequency resolution (reduction of the width of the normalized frequency mismatch function) by 100 %. With the predominant multiplicative effect of these fluctuations, a twofold increase in the number of radio pulses results in an improvement in the frequency resolution by about 40 %. The developed method is of great theoretical and practical importance for the further development of the radar theory of high-speed and maneuvering individual and group aerodynamic objects.

Automation of calculations of cutting modes taking into account the wear of cubic boron nitride tools when applying solid lubricants

2021 ◽  
pp. 67-70
Author(s):  
Keyword(s):  
Boron Nitride ◽  
High Speed ◽  
Solid Lubricant ◽  
Cubic Boron Nitride ◽  
High Speed Steel ◽  
Solid Lubricants ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Ceramic Bond ◽  
Calculation System

The effect of a solid lubricant on the wear of cubic boron nitride grinding wheels on a ceramic bond of different hardness and grain size in the processing of high-speed steel is investigated. The dependences of the change in the wear of cubic boron nitride on the parameters of the processing mode are determined. An automated calculation system is proposed to control the consumption of cubic boron nitride grinding wheels in production conditions. Keywords: solid lubricant, grinding, high speed steel, cubic boron nitride grinding wheel, consumption, wear, grinding mode. [email protected]

scholarly journals Design of a High-Speed Prosthetic Finger Driven by Peano-HASEL Actuators

2020 ◽  
Vol 7 ◽  
Author(s):  
Zachary Yoder ◽  
Nicholas Kellaris ◽  
Christina Chase-Markopoulou ◽  
Devon Ricken ◽  
Shane K. Mitchell ◽  
...  
Keyword(s):  
High Speed ◽  
Kinematic Model ◽  
Electrical Energy ◽  
Dc Motor ◽  
Self Healing ◽  
Force Output ◽  
Prosthetic Limbs ◽  
Neuromuscular Systems ◽  
Soft Actuators ◽  
Prosthetic Finger

Current designs of powered prosthetic limbs are limited by the nearly exclusive use of DC motor technology. Soft actuators promise new design freedom to create prosthetic limbs which more closely mimic intact neuromuscular systems and improve the capabilities of prosthetic users. This work evaluates the performance of a hydraulically amplified self-healing electrostatic (HASEL) soft actuator for use in a prosthetic hand. We compare a linearly-contracting HASEL actuator, termed a Peano-HASEL, to an existing actuator (DC motor) when driving a prosthetic finger like those utilized in multi-functional prosthetic hands. A kinematic model of the prosthetic finger is developed and validated, and is used to customize a prosthetic finger that is tuned to complement the force-strain characteristics of the Peano-HASEL actuators. An analytical model is used to inform the design of an improved Peano-HASEL actuator with the goal of increasing the fingertip pinch force of the prosthetic finger. When compared to a weight-matched DC motor actuator, the Peano-HASEL and custom finger is 10.6 times faster, has 11.1 times higher bandwidth, and consumes 8.7 times less electrical energy to grasp. It reaches 91% of the maximum range of motion of the original finger. However, the DC motor actuator produces 10 times the fingertip force at a relevant grip position. In this body of work, we present ways to further increase the force output of the Peano-HASEL driven prosthetic finger system, and discuss the significance of the unique properties of Peano-HASELs when applied to the field of upper-limb prosthetic design. This approach toward clinically-relevant actuator performance paired with a substantially different form-factor compared to DC motors presents new opportunities to advance the field of prosthetic limb design.

ESSENTIAL REQUIREMENTS FOR ROADBED DESIGN OF HIGHSPEED RAIL LINES

2018 ◽  
pp. 36-48
Author(s):  
Alexey Kolos ◽  
Andrey Petryayev ◽  
Irina Kolos ◽  
Vadim Govorov ◽  
Evgeniy Shekhtman
Keyword(s):  
Russian Federation ◽  
High Speed ◽  
Western Europe ◽  
System Analysis ◽  
Practical Importance ◽  
Design Standards ◽  
High Speed Networks ◽  
High Speed Network ◽  
Scientific Justification ◽  
The Russian Federation

Objective: Scientific justification of requirements to roadbed design of high-speed networks (HSN) for the purpose of constructing “Moscow–Kazan–Yekaterinburg” railroad line, as well as implementation of “Eurasia” and “Yekaterinburg–Chelyabinsk” HSN projects. Methods: The analysis of modern roadbed design standards for HSN was carried out. The justification of HSN roadbed norms and requirements involved system analysis of HSN engineering and construction in Western Europe, China, Japan and other countries with well-developed high-speed network. Results: The fundamental principles and requirements, which are to be taken as a basis of HSN roadbed engineering, were determined. Practical importance: The obtained results are to be used in HSN roadbed engineering and construction, performed on the territory of the Russian Federation.

Safety management of high-speed railway transport

2017 ◽  
pp. 105-118
Author(s):  
Vladimir Shmatchenko ◽  
Pavel Plekhanov
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
High Speed ◽  
A Priori Estimates ◽  
Safety Management ◽  
Practical Importance ◽  
International Standards ◽  
Railway Transport ◽  
High Speed Railway ◽  
Safety Control

Objective: To determine the main approaches to safety management of high-speed railway transport on the basis of modern international and domestic practices in the specified sphere. Methods: Analysis methods of security risks on railway transport were considered in accordance with modern international standards of management of interconnected indices’ complex, which include reliability, availability, maintainability and safety and cost (Life Cycle Cost – LCC) at all stages of transportation systems’ life cycle: EN 50126 (IEC 62278), EN 50128 (IEC 62279), EN 50129 (IEC 62425) and IEC 60300-3-3. Results: The main approaches to safety measures of high-speed railway lines (VSM) were detected. The former involve using a lifecycle concept of engineering systems and facilities, management methodology of RAMS/LCC interconnected indices’ complex at all stages of a life cycle, wide application of the process approach and the tools of quality and safety management systems, development and implementation of technological maturity assessment methodology for security management activities, as well as object-oriented and coherent improvement of regulatory base, the systems of administrative and control and permission authorities, technical and technological development, management of external, inland and allocated risks under market relations. Practical importance: The examined approaches of VSM safety control make it possible to obtain a priori estimates of safety control processes and thus determine the achieved level of safety together with the levels of technological maturity of railway organizations’ processes.

THE IMPROVEMENT OF WHEEL TREAD REPROFILING PROCESS

2017 ◽  
pp. 120-128
Author(s):  
Igor Ivanov ◽  
Dmitriy Kononov ◽  
Sergey Urushev
Keyword(s):  
High Speed ◽  
Performance Enhancement ◽  
Practical Knowledge ◽  
Practical Importance ◽  
Rolling Stock ◽  
Speed Profile ◽  
Operating Life ◽  
Operational Life ◽  
High Speed Grinding ◽  
Process Solutions

Object: To show the lack of wheelset operating life efficiency use in case traditional methods of wheel tread reprofiling were used in the process of repair works. To consider the possibilities of further improvement of this process on the basis of new reprofiling technologies, using the deep and high-speed grinding. Methods: The methods of wheel tread reprofiling were analyzed, the effective process solutions, based on theoretical conclusions and current practical knowledge, were studied. Results: Wheel set wastage in case of using the traditional ways of reprofiling was estimated. Preliminary parameters of wheelset reprofiling modes using high-speed grinding were estimated, providing for the increase in wheel set operational life and reprofiling performance enhancement. Practical importance: The appropriateness of rolling stock wheel tread reprofiling, by using the method of infeed high-speed profile grinding, was presented. The obtained results may be applied in the development of requirements specification for wheel tread reprofiling machine at repair facilities of the Russian Railways.

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