scholarly journals Study of Aerosol Charging in Electro-Aerosol Generator

2017 ◽  
Vol 7 (2) ◽  
pp. 69-77
Author(s):  
P. L. Lekomtsev ◽  
A. V. Savushkin ◽  
E. V. Dresviannikova ◽  
A. M. Niyazov
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Plant Protection ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Preventive Treatment ◽  
Convection Current ◽  
Aerosol Generation ◽  
Aerosol Generator ◽  
Basic Characteristics

Abstract The urgency of the study is conditioned by the necessity of perfection of the methods of electro-aerosol disinfection and disinsection of the air and the surfaces of premises, medical and preventive treatment of animals, and plant protection. The objective of the paper is aimed at revealing the regularities of electro-physical processes when charging an aerosol in electro-aerosol generators, improvement of the methods of electro-aerosol generation. The leading approach to the research of this problem is mathematical modelling of electrotechnical, dynamic and kinetic processes in electro-aerosol generators, allowing revealing the basic regularities of electro-aerosol generation. Experimental studies are aimed at assessment of the main characteristic of the electro-aerosol generator – convection current. As a result of the studies, a mathematical model of electro-aerosol generation with the mechanical method of atomization was obtained. The regularities of charging a fluid thread, arising at the edge of the generator, when applying electric field. The configuration of the electric field of cylindrical electrodes, taking into account the influence of the bulk charge of the electro-aerosol cloud, was considered. Electrostatic pressure of the electric field of the generator on fluid streams was taken into consideration. An equation for determining the average radius of drops of the electro-aerosol during mechanical atomization by the perforated cage was obtained. The mathematical model of electro-aerosol generation is obtained in the form of the equation of convection current, being one of the basic characteristics of the process of electro-aerosol generation, allowing defining the efficiency of electrization of aerosol particles and the degree of their fragmentation. Theoretical calculations are verified experimentally. Materials of the paper can be useful for the researchers, post-graduate students, engineers, engaged in designing, manufacturing and exploiting electro-aerosol equipment.

scholarly journals Mathematical Model of Bainitic Transformation in Austempered Ductile Iron

2017 ◽  
Vol 17 (4) ◽  
pp. 200-206
Author(s):  
I. Olejarczyk-Wożeńska ◽  
H. Adrian ◽  
B. Mrzygłód ◽  
M. Głowacki
Keyword(s):  
Mathematical Model ◽  
Grain Size ◽  
Ductile Iron ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Bainitic Transformation ◽  
Transformation Model ◽  
Austenite Grain Size ◽  
Ttt Diagram ◽  
Austenite Grain

AbstractA mathematical model of austenite - bainite transformation in austempered ductile cast iron has been presented. The model is based on a model developed by Bhadeshia [1, 2] for modelling the bainitic transformation in high-silicon steels with inhibited carbide precipitation. A computer program has been developed that calculates the incubation time, the transformation time at a preset temperature, the TTT diagram and carbon content in unreacted austenite as a function of temperature. Additionally, the program has been provided with a module calculating the free energy of austenite and ferrite as well as the maximum driving force of transformation. Model validation was based on the experimental research and literature data. Experimental studies included the determination of austenite grain size, plotting the TTT diagram and analysis of the effect of heat treatment parameters on the microstructure of ductile iron. The obtained results show a relatively good compatibility between the theoretical calculations and experimental studies. Using the developed program it was possible to examine the effect of austenite grain size on the rate of transformation.

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 and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

2017 ◽  
Author(s):  
Haibo Ge ◽  
Lei Pan ◽  
Piaoping Tang ◽  
Ke Yang ◽  
Mian Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Bond Functionalization ◽  
Aliphatic Ketones ◽  
Site Selectivity ◽  
Mechanistic Investigation ◽  
Palladium Catalyzed ◽  
Metal Catalyzed ◽  
Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp<sup>3</sup> carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp<sup>3</sup>)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp<sup>3</sup>)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.<br><br>

Mathematical model to predict the characteristics of polarization in dielectric materials: The concept of piezoelectrcity and electrostriction

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Lead Zirconate Titanate ◽  
Dielectric Material ◽  
Strain Curve ◽  
Dielectric Materials ◽  
Lead Zirconate ◽  
Simulation Software ◽  
Constitutive Law ◽  
Basic Material

Model was developed for the prediction of polarization characteristics in a dielectric material exhibiting piezoelectricity and electrostriction based on mathematical equations and MATLAB computer simulation software. The model was developed based on equations of polarization and piezoelectric constitutive law and the functional coefficient of Lead Zirconate Titanate (PZT) crystal material used was 2.3×10-6 m (thickness), the model further allows the input of basic material and calculation of parameters of applied voltage levels, applied stress, pressure, dielectric material properties and so on, to generate the polarization curve, strain curve and the expected deformation change in the material length charts. The mathematical model revealed that an application of 5 volts across the terminals of a 2.3×10-6 m thick dielectric material (PZT) predicted a 1.95×10-9 m change in length of the material, which indicates piezoelectric properties. Both polarization and electric field curve as well as strain and voltage curve were also generated and the result revealed a linear proportionality of the compared parameters, indicating a resultant increase in the electric field yields higher polarization of the dielectric materials atmosphere.

Matrix Acidization with Highly Reactive Acids

1971 ◽  
Vol 11 (04) ◽  
pp. 390-398 ◽  
Author(s):  
J.A. Guin ◽  
R.S. Schechter
Keyword(s):  
Mathematical Model ◽  
Pore Structure ◽  
Pore Size ◽  
Acid Treatment ◽  
Explicit Knowledge ◽  
Experimental Studies ◽  
Design Procedure ◽  
Permeability Change ◽  
Pore Size Distributions ◽  
Matrix Acidization

Abstract A mathematical model representing the changes in pore structure attending the invasion of a porous material by a reactive fluid tending to dissolve the solid bas previously been tested and found to be valid. This mathematical model is solved by a simulation procedure using Monte Carlo techniques. The results so obtained are indicative of the acidization of sandstone using a last-reacting acid (diffusion limited). A correlation relating the permeability improvement to the change in porosity is presented and found to be applicable to a wide class of initial pore-size distributions. This means that the designer need not have explicit knowledge of the initial pore structure to utilize the correlation. The generality of the correlation stems from the fact that after exposure to fast-acting acids (diffusion-controlled reactions) wormholing tends to occur in all porous matrices, and the acid allows preferentially through these channels. Thus, the process is independent of the fine pore structure since the fine pores receive no acid Wormholing bas been observed in almost all experimental studies of acidization, thus further confirming the validity of the model. Introduction Matrix acidization as practiced in the petroleum industry is a simple operation. Acids treated so as to prevent their corrosive attack on metal parts contacted are pumped down the wellbore and forced into the pore spaces of an oil-bearing rock. The rate of penetration is normally maintained small enough to prevent fracturing of the reservoir The aim of matrix acidization is to enhance the permeability of the region around the wellbore by permeability of the region around the wellbore by dissolving either a portion of the rock or of the foreign impurities that may have been introduced during the drilling operations. The success of this technique of oilwell stimulation is attested to by the fact that a significant fraction of the acids used for stimulation are injected at matrix rates. There were, moreover, in excess of 87 million gal of hydrochloric acid used last year in carbonate formations with many other special purpose acids such as acetic and formic having also been used for stimulation purposes. Despite the fact that acids have long been routinely used as a means of stimulating oil wells to greater production, there is, as yet, no reliable design procedure incorporating all of the essential features into a prediction of the new production that will result from a given acid treatment of a particular well. This lack of a design procedure particular well. This lack of a design procedure has been responsible for the rather minimal efforts expended in obtaining meaningful reaction rate data, for there is very little enthusiasm for obtaining data which cannot be put to practical application. This paper is an extension of some recently reported work on predicting the permeability change resulting from acid treatment of an oil-bearing rock. It has been proposed that the changes in the microstructure owing to acidization in a porous rock can be simulated by considering the effect of acidization of a collection of small, randomly distributed capillaries that are interconnected to the extent that a fluid will be conducted from point to point under the influence of an external pressure gradient. This model, the capillaric model, has been used with varying success in understanding the behavior of porous media. The use of the capillaric model in determining only the results of the evolution of a pore-size distribution, rather than as a vehicle for predicting a number of mare or less independent phenomena, such as capillary pressure curves and dispersion, is, as has been pressure curves and dispersion, is, as has been noted by Schechter and Gidley, a more limited and perhaps attainable goal. Taking the capillaric model to be correct, Guin et al. have shown that an equation relating the porosity change and the permeability change caused by an ideally retarded permeability change caused by an ideally retarded acid can be derived without any assumptions. SPEJ P. 390

THE HEAP PARTS MOVEMENT ON THE SHAREBOARD SURFACE OF THE POTATO HARVESTING MACHINE

2021 ◽  
Vol 14(63) (1) ◽  
pp. 127-140
Author(s):  
Serhii HRUSHETSKYI ◽  
Vitaly YAROPUD ◽  
Ihor KUPCHUK ◽  
Ruslana SEMENYSHENA
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Separation Process ◽  
Kinematic Parameters ◽  
Quality Performance ◽  
Machine Operation ◽  
Degree Of Damage ◽  
Total Capacity ◽  
Comparison Of The Results

The article is devoted to the problem of the reduction of tubers mechanical damages while providing qualitative indicators of the potato heap separation process. Theoretical and experimental dependences of the influence of design and kinematic parameters of the machine operation on the quality performance are obtained. Within the field of experimental studies, a field installation was made to investigate the potato harvester as a whole on the efficiency of separation, the degree of damage, the magnitude of losses and the total capacity for aggregation. Comparison of the results of theoretical and experimental studies showed that the developed mathematical model of the process of separation of potato heap is adequate.

Electric Field Effects on Natural Convection in Enclosures

1986 ◽  
Vol 108 (4) ◽  
pp. 749-754 ◽  
Author(s):  
D. A. Nelson ◽  
E. J. Shaughnessy
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Convective Heat Transfer ◽  
Heat Transfer Rate ◽  
Convective Heat ◽  
Transfer Rate ◽  
Stokes Equations ◽  
Experimental Studies ◽  
Navier Stokes ◽  
First Order Theory

The enhancement of convective heat transfer by an electric field is but one aspect of the complex thermoelectric phenomena which arise from the interaction of fluid dynamic and electric fields. Our current knowledge of this area is limited to a very few experimental studies. There has been no formal analysis of the basic coupling modes of the Navier–Stokes and Maxwell equations which are developed in the absence of any appreciable magnetic fields. Convective flows in enclosures are particularly sensitive because the limited fluid volumes, recirculation, and generally low velocities allow the relatively weak electric body force to exert a significant influence. In this work, the modes by which the Navier–Stokes equations are coupled to Maxwell’s equations of electrodynamics are reviewed. The conditions governing the most significant coupling modes (Coulombic forces, Joule heating, permittivity gradients) are then derived within the context of a first-order theory of electrohydrodynamics. Situations in which these couplings may have a profound effect on the convective heat transfer rate are postulated. The result is an organized framework for controlling the heat transfer rate in enclosures.

scholarly journals The Influence of Water and Mineral Oil On Volumetric Losses in a Hydraulic Motor

2017 ◽  
Vol 24 (s1) ◽  
pp. 213-223 ◽  
Author(s):  
Pawel Śliwiński
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Hydraulic Motor ◽  
Small Constant ◽  
Influence Of Water ◽  
The Difference ◽  
Lubricating Properties

Abstract In this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquids, including water. The sources of leaks in this motor are also characterized and described. On this basis, a mathematical model of volumetric losses and model of effective rotational speed have been developed and presented. The results of calculation of volumetric losses according to the model are compared with the results of experiment. It was found that the difference is not more than 20%. Furthermore, it has been demonstrated that this model well describes in both the volumetric losses in the motor supplied with water and oil. Experimental studies have shown that the volumetric losses in the motor supplied with water are even three times greater than the volumetric losses in the motor supplied with oil. It has been shown, that in a small constant stream of water the speed of the motor is reduced even by half in comparison of speed of motor supplied with the same stream of oil.

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