Rostov-na-Donu, Russia
Rostov-na-Donu, Russia

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Pustovetov M.Yu.,Rostov State Transport University
2016 Dynamics of Systems, Mechanisms and Machines, Dynamics 2016 | Year: 2016

This article provides the equations of mathematical model of three-phase asynchronous electric machine recorded in the three-phase stator reference frame. Described in detail is the possibility of the proposed mathematical model. In particular, the possibility of modeling the rotor currents at their actual frequency. It is also an example of modeling a complex mode of asynchronous machine - its use as rotary electromechanical phase splitter onboard of a railway electric rolling stock. In this case, the machine receives the supply voltage from the secondary winding of a single-phase transformer. Then it converts it into three-phase voltage to three-phase consumers such as induction motors loaded by fans and air compressors. Simulation results show the adequacy of the proposed mathematical model of asynchronous electric machine. © 2016 IEEE.

Demekhin P.V.,University of Heidelberg | Demekhin P.V.,Rostov State Transport University | Cederbaum L.S.,University of Heidelberg
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

The dynamics of atomic levels resonantly coupled by a coherent and intense short high-frequency laser pulse is discussed and it is advocated that this dynamics is sensitively probed by measuring the spectra of the particles emitted. It is demonstrated that the time envelope of this laser pulse gives rise to two waves emitted with a time delay with respect to each other at the rising and falling sides of the pulse, which interfere in the time domain. By computing numerically and analyzing explicitly analytically a showcase example of sequential two-photon ionization of an atom by resonant laser pulses, we argue that this dynamic interference should be a general phenomenon in the spectroscopy of strong laser fields. The emitted particles do not have to be photoelectrons. Our results allow us also to interpret the already studied resonant Auger effect of an atom by intense free-electron laser pulses, and also to envisage experiments in which photons are emitted. © 2012 American Physical Society.

Demekhin P.V.,University of Heidelberg | Demekhin P.V.,Rostov State Transport University | Cederbaum L.S.,University of Heidelberg
Physical Review Letters | Year: 2012

The ionization of an atom by a high-frequency intense laser pulse, where the energy of a single photon is sufficient to ionize the system, is investigated from first principles. It is shown that as a consequence of an ac Stark effect in the continuum, the energy of the photoelectron follows the envelope of the laser pulse. This is demonstrated to result in strong dynamic interference of the photoelectrons of the same kinetic energy emitted at different times. Numerically exact computations on the hydrogen atom demonstrate that the dynamic interference spectacularly modifies the photoionization process and is prominently manifested in the photoelectron spectrum by the appearance of a distinct multipeak pattern. The general theory is well approximated by explicit analytical expressions that allow for a transparent understanding of the discovered phenomena and for making predictions on the dependence of the measured spectrum on the pulse. © 2012 American Physical Society.

Demekhin P.V.,University of Heidelberg | Demekhin P.V.,Rostov State Transport University | Chiang Y.-C.,University of Heidelberg | Cederbaum L.S.,University of Heidelberg
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

The dynamics of the resonant Auger (RA) process of the core-excited C *O(1s-1π*,vr=0) molecule in an intense x-ray laser field is studied theoretically. The theoretical approach includes the analog of the conical intersections of the complex potential energy surfaces of the ground and "dressed" resonant states due to intense x-ray pulses, taking into account the decay of the resonance and the direct photoionization of the ground state, both populating the same final ionic states coherently, as well as the direct photoionization of the resonance state itself. The light-induced nonadiabatic effect of the analog of the conical intersections of the resulting complex potential energy surfaces gives rise to strong coupling between the electronic, vibrational, and rotational degrees of freedom of the diatomic CO molecule. The interplay of the direct photoionization of the ground state and of the decay of the resonance increases dramatically with the field intensity. The coherent population of a final ionic state via both the direct photoionization and the resonant Auger decay channels induces strong interference effects with distinct patterns in the RA electron spectra. The individual impact of these physical processes on the total electron yield and on the CO+(A2Π) electron spectrum are demonstrated. © 2011 American Physical Society.

Kolesnikov I.V.,Rostov State Transport University
Journal of Friction and Wear | Year: 2016

The interconnection of triboelectric, segregation-diffusion and tribochemical processes at metal–polymer contact area have been revealed. A system approach allows the methods for control of friction properties of metal–polymer friction assemblies to be developed. These methods are based on data that describe the effect of the triboelectric field on diffusion processes in metal–polymer tribosystems and the formation of friction transfer film. The formation of the transfer film has been studied by IR-spectroscopy, and element content on the grain boundaries–by Auger-spectroscopy. © 2016, Allerton Press, Inc.

Konstantin Y.,Rostov State Transport University
Advances in Intelligent Systems and Computing | Year: 2016

Automation of control pneumatic brakes allows improve safety by eliminating the human factor and to ensure energy-optimized operation of train motion. Subsystem of automatic control pneumatic brakes is part of the on-board autopilot system of the train. Based on the analysis of existing relay systems of automatic control of the brake is proposed and studied the control algorithm that uses nonlinear feedback from pressure in the brake cylinders and derivative of error speed control. To calculate the feedback signal used mathematical apparatus of fuzzy logic. Computational experiments were conducted using a software simulator of driver of the freight locomotive that is part of the teaching-research laboratory and training complex “Virtual railway RSTU”. In paper investigated the stabilization mode the velocity of the train on long downhill with a slope of 9 % with application of the pneumatic brakes. Shows efficiency of the proposed algorithm in comparison with known. © Springer International Publishing Switzerland 2016.

Mukutadze M.A.,Rostov State Transport University
Procedia Engineering | Year: 2016

This paper presents the analytical model of the radial bearing of the finite length with the two-layer porous insert obtained on the basis of the dimensionless equations of movement of a viscous incompressible lubricant in an operating clearance and in porous layers of a bearing sleeve and continuity equations as well. We are analyzing the case when permeability of porous layers on the border of section of a two-layer insert accepts one value. The lubricant moves in a circumferential direction through a bore in a bearing body and the subsequent filtration occurs through insert pores. Permeability anisotropy of porous layers is taken into consideration in radial and circumferential directions. As a result of the given task, we have obtained the field of speeds and pressure in porous layers and in the lubricant layer. Analytical dependences for components of a vector of supporting force and the friction moment have been found, and we have also defined the loading factor and friction factor. Moreover, in our calculations we have revealed and used the parameter characterizing specificity of lubrication feeding in a circumferential direction. It is proved that the rational mode of operation is reached by a design of a two-layer porous insert given when the resistance factor increases more intensively and from the parameter ψ, and from a relative eccentricity ϵ in comparison with the bearing having a single-layer insert. Hence, anisotropy of permeability of porous layers in a circumferential and radial direction has a defined possibility of practical application of this new model. © 2016 Published by Elsevier Ltd.

Mukutadze A.M.,Rostov State Transport University
Procedia Engineering | Year: 2016

On the basis of the Darcy's equations which define the lubrication flow in porous layers, and the Reynolds's modified equation, we solve the problem of an unsteady movement of viscous incompressible lubrication in the clearance of a porous damper. The peculiarity of this solution is a simultaneous account of dependence of lubrication viscosity and permeability of porous barrel. As a result, we have found the field of pressure in a porous and lubricant layer, analytical dependences for forces in the oily film as well as the equations describing non-stationary and stationary movement of the shaft center have been obtained. Besides, the module of unbalance transmitted force and also stationary and non-stationary drive factors have been established. It is proved, that taking into consideration a simultaneous account of dependence of the lubrication viscosity and permeability of the porous barrel, the damper works more steadily. The received specified analytical models have allowed establishing of the influence of some additional factors, and also making the comparative analysis of newly received results and already available ones. It has confirmed the great connection of a new model with a real practice. © 2016 The Authors.

Koropets P.,Rostov State Transport University
Transport Problems | Year: 2014

On the model of a locomotive traction drive in a slipping mode, it is demonstrated how the electromagnetic transient processes in the traction motor may be accounted for using the energy balance method for assessing the stability of the system with respect to frictional self-oscillations. The regions of existence of frictional self-oscillations in the parameter space of the drive are built. The proposed method differs from the prior art in that it can be used to analyze the stability of a wide class of dynamical systems with small damping, containing both oscillatory and inertial units. © Copyright 2014 by Wydawnictwo Politechniki Śla{ogonek}skiej Gliwice.

Ljabach N.N.,Rostov State Transport University
Proceedings of the 19th International Conference on Soft Computing and Measurements, SCM 2016 | Year: 2016

In this article, the main lines of research of intelligence rate for technical and process systems have been analyzed. The methods of intelligence rate evaluation and enhancement have been developed. This article represents and gives vindication of analytical relations used to evaluate the intelligence rate of intelligent systems. © 2016 IEEE.

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