Applied Mechanics and Materials Vol. 792

Abstract: Mathematical model of appearance and progress of noise characteristics in super-power electric arc steel furnaces is considered in the paper. It is shown that noise generation is coupled with pulsations of axial plasma flows in arc discharge caused by fluctuations of electrodynamic pressure on discharge column formed by interaction between its own magnetic field and current flowing in the arc. Simulation results have shown that pressure in arc axis alternates at frequency 100 Hz with amplitude 6600 N/m² for arc current 80 kA. Basic frequencies of arc noise are aliquot to 100 Hz, that fact is verified by exploitation practice of arc steel furnaces. Sound intensity level in workspace riches 160 dB, but thanks to shielding by case and fused metal and slag it falls to 115–120 dB on service area of furnace. It has shown that maximal amplitudes in frequency spectrum of the noise are in range 5–150 Hz. Generated noise amplitudes and frequency ranges depend on arc discharges' resistance, which are defined by ionization level of gases. According to Saha equation, iron vapor is ionized by 70 %, calcium vapor – by 95 %, and ionization level of air is no more than 1.5 %. It has been experimentally shown that in melting of stock coated with lime noise intensity is decreased by 6–8 % against no-lime iron melting because of lower calcium ionization potential (6.11 eV). It has been ascertained that for long arc with high voltages the sound intensity is decreased by 3–4 % as compared with short arc of the same current. It has shown that suppression of low-frequency components of noise energy is possible by optimization of electromechanical oscillations of electrodes, electrode-holders and cable strips, additionally to inclusion lime in stock mixture. The appropriateness of improvement electric arc furnaces hermeticity and development of the furnaces for operation with lowered currents and enlarged transformers' voltages have been approved.

Abstract: One application of induction heating is a planetary reactor for deposition of compound semiconductor layers from the gas phase. High temperature needed for the process is provided by a “pancake” induction coil. Temperature distribution in the reactor influences the deposition quality as well as the lifetime of the reactor components. The induction coil shape has been improved by numerical modelling combined with automatic optimization. The developed two-and three-dimensional models include coupled electromagnetic and thermal calculations to take into account temperature dependent material properties. Three-dimensional structural analysis, based on the predicted temperature distribution, was used to estimate the level of the appeared thermal stresses in the reactor parts. The received optimal design of the induction coil has been successfully tested in the industrial planetary reactor.

Abstract: The calculation algorithm of the melt surface shape of the induction crucible furnaces (ICF) taking into account the variable melt level in crucible is developed. The special-purpose software package for calculation of the height and melt surface shape in ICF is developed. The investigation results of the melt surface shape and its influence upon energy and electric characteristics of the ICF are presented.

Abstract: In this research the method of the calculation of the power losses in DC electromagnet through eddy currents, which are analog of the viscous friction, is presented. The influence of these currents on the operation of the vibroisolator with the electromagnetic stiffness compensator is estimated. The losses of the power on eddy currents are less than 1 per cent of the electromagnet power itself and the compensator totally. The example of the calculation of the losses for eddy currents in steel conductor is also shown.

Abstract: This research presents the traction characteristic of the stiffness compensator using the odd polynomial. Due to the various components of the polynomial we can get any stiffness characteristics. The calculation of the polynomial coefficients is presented. For the representation of the characteristic in automatic control systems the harmonic linearization coefficients are obtained for the polynomial n-th degree, which corresponds accurately to the description of the precise method.

Abstract: The article presents the research aimed at improving the efficiency of the diesel engines running. The advantages and disadvantages of the existing systems of the starter starting systems of diesel locomotives are considered. Brainstorming ideas on the issue of the calculation and selection of the alternative circuitry power circuit pulse converter starting system of diesel engines are described in the paper. An example of calculating the regulating characteristics of the pulse converter and the efficiency of the proposed circuit design is reported.

Abstract: The article explores possible structures of road public transit vehicles, distinguishing by energy sources. Available primary energy sources and energy storage devices are compared. The most promising structures are chosen and their main properties are estimated. Some recommended strategies then follow.

Abstract: Everyday the mankind consumes more and more energy, in this regard the stocks of traditional sources of this energy are decreased. Much attention has always been given to the problem of effective energy saving in transport. The environmental degradation is in parallel to the problem. The hybrid vehicle invention can be the solution of the problems given. The research considers the development and invention of the energy saving hybrid vehicle. The vehicle is driven by means of power station, the differential peculiarity of which is two energy sources usage and two types of engine, electric-powered and heat engine. In this paper the arrangements of combined and hybrid power stations for vehicles with heat-engines are developed. The key advantage of such vehicles is a fuel consumption reduction and the emission of harmful agents to the atmosphere.

Abstract: The whole model of adaptive optics system of energy and information transfer should include a model of an active element [1] construction of which is defined by parameters of the system and beam control algorithm. In the algorithm of full-field phase conjugation a nonlinear crystal or two flexible mirrors with a layer of free space between them are usually employed [2, 3], while a system of phase conjugation requires a flexible mirror as an active element [4]. In the paper the model of a flexible mirror is considered which takes into account dynamic oscillation of reflecting surface.

Abstract: The results of experimental study of the exhaust process of the piston internal combustion engine are presented in the article. A method for improving the cleaning of the cylinder from the exhaust gas on the basis of the effect the ejection is proposed in the paper. Dependences of change of the instantaneous gas velocity on the angle of rotation of the crankshaft in the exhaust tract of a different configuration (with ejector and without it) are listed in the article.