scholarly journals Hydrodynamics features in cavitation devices under tangent medium input

2018 ◽  
Vol 244 ◽  
pp. 01001
Author(s):  
Tetiana Vitenko ◽  
Paweł Droździel ◽  
Nazar Horodyskyi
Keyword(s):  
Experimental Studies ◽  
Flow Simulation ◽  
Gas Bubbles ◽  
Hydrodynamic Cavitation ◽  
Technological Parameters ◽  
Design Features ◽  
Volume Increase ◽  
Mode Of Operation ◽  
Comparison Of The Results ◽  
Fluid Flow Modeling

Theoretically analysed design features of the working section of a hydrodynamic cavitation device with swirling input. Using the numerical methods of SolidWorks software and the Flow simulation module, fluid flow modeling was performed to describe similar processes. The comparison of the results of visual and experimental studies has been carried out. Visual observations indicate that the life cycle of vapor-gas bubbles and cavities in the design under study can be divided into several periods, in particular the formation of vapor-gas bubbles, their growth, generation of cavities, their volume increase, transformation and destruction. The influence of input and output hydrodynamic and technological parameters of the flow and design features on the character of the cavitation area and the form of cavitation were studied. According to the results of theoretical and experimental research, rational mode of operation of the cavitation device is proposed.

Mathematical Model of Melting of Solid Sulfur Particles when Loaded into a Melting Bath

2020 ◽  
Vol 836 ◽  
pp. 1-5
Author(s):  
Pavel V. Iakovlev ◽  
Vladimir A. Lebedev
Keyword(s):  
Solid Phase ◽  
Experimental Studies ◽  
Melting Rate ◽  
Solid Particles ◽  
Technological Parameters ◽  
Liquid Sulfur ◽  
Mode Of Operation ◽  
Loading Device ◽  
Molten Liquid ◽  
Device Operation

The study solved the problem of determining the technological mode of operation of the device for loading solid lumpy and granulated sulfur into a melting bath with molten liquid sulfur. For this it is necessary to solve two main problems: to determine the method of loading solid sulfur into the melt, to calculate the main design and technological parameters to ensure the required performance of the smelting bath. As a result of experimental studies, the mode of operation of the loading device was obtained, during which the partial melting of the surface of sulfur particles in the surface layer of the melt occurred. This led to the adhesion of particles to each other, the formation of conglomerates having a size that is much larger compared with that of particles of the initial particle size distribution. As a result of this phenomenon, the melting rate and the melting bath were significantly reduced, filled with a solid phase. As a result of the study, a model was developed and the problem of calculating the limiting modes of the loading device operation was solved for preventing solid particles from sticking together.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

Validation of Numerical Models Used for Designing the Composite Blade for ILX-27 Rotorcraft

2019 ◽  
Vol 2019 (4) ◽  
pp. 23-31
Author(s):  
Jakub Wilk ◽  
Radosław Guzikowski
Keyword(s):  
Epoxy Composite ◽  
Numerical Models ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Laminate Glass ◽  
Composite Blade ◽  
Real Objects ◽  
Validation Procedure ◽  
Research Objects ◽  
Comparison Of The Results

Abstract The paper presents the validation procedure of the model used in the analysis of the composite blade for the rotor of the ILX-27 rotorcraft, designed and manufactured in the Institute of Aviation, by means of numerical analyses and tests of composite elements. Numerical analysis using finite element method and experimental studies of three research objects made of basic materials comprising the blade structure – carbon-epoxy laminate, glass-epoxy composite made of roving and foam filler – were carried out. The elements were in the form of four-point bent beams, and for comparison of the results the deflection arrow values in the middle of the beam and axial deformations on the upper and lower surfaces were selected. The procedure allowed to adjust the discrete model to real objects and to verify and correct the material data used in the strength analysis of the designed blade.

Dynamic Characterization of a Valveless Micropump Considering Entrapped Gas Bubbles

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Songjing Li ◽  
Jixiao Liu ◽  
Dan Jiang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
Chamber Pressure ◽  
Dynamic Characterization ◽  
Valveless Micropump ◽  
Performance Deterioration ◽  
Trapped Gas

Unexpected gas bubbles in microfluidic devices always bring the problems of clogging, performance deterioration, and even device functional failure. For this reason, the aim of this paper is to study the characterization variation of a valveless micropump under different existence conditions of gas bubbles based on a theoretical modeling, numerical simulation, and experiment. In the theoretical model, we couple the vibration of piezoelectric diaphragm, the pressure drop of the nozzle/diffuser and the compressibility of working liquid when gas bubbles are entrapped. To validate the theoretical model, numerical simulation and experimental studies are carried out to investigate the variation of the pump chamber pressure influenced by the gas bubbles. Based on the numerical simulation and the experimental data, the outlet flow rates of the micropump with different size of trapped gas bubbles are calculated and compared, which suggests the influence of the gas bubbles on the dynamic characterization of the valveless micropump.

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.

scholarly journals RESEARCH OF THE OF BULK MATERIAL MOVEMENT PROCESS IN THE INACTIVE ZONE BETWEEN SCREW SECTIONS

2020 ◽  
Vol 60 (1) ◽  
pp. 261-268
Author(s):  
O.M. Trokhaniak ◽  
R.B. Hevko ◽  
O.L. Lyashuk ◽  
T.A. Dovbush ◽  
B.V. Pohrishchuk ◽  
...  
Keyword(s):  
Optimal Design ◽  
Bulk Material ◽  
Experimental Studies ◽  
Screw Conveyor ◽  
Technological Parameters ◽  
Movement Process ◽  
Curved Paths ◽  
Agricultural Materials

The article presents the results of theoretical and experimental studies of the process of moving bulk material in the inactive zone between hinged screw sections of a flexible screw conveyor. The influence of the gap between the edges of adjacent screw sections and the magnitude of their circular displacement on the process of continuous transportation of bulk material is presented. The results of theoretical and experimental studies are compared. This will allow choosing the optimal design, kinematic and technological parameters of the developed sectional screw working body when transporting bulk agricultural materials along curved paths, both in horizontal and inclined directions, as well as along curved paths.

scholarly journals RESEARCH OF PHYSICAL AND MECHANICAL PROPERTIES OF WOOD-FIBER MATERIALS

2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Strength Properties ◽  
Grinding Process ◽  
Technological Parameters ◽  
Fiber Materials ◽  
Traditional Construction

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.

scholarly journals Heat transfer in the mold during vertical continuous casting of steel

2018 ◽  
pp. 26-30
Author(s):  
E. I. Marukovich ◽  
E. B. Demchenko
Keyword(s):  
Heat Transfer ◽  
Temperature Regime ◽  
Thermal State ◽  
Effective Means ◽  
Experimental Studies ◽  
Casting Process ◽  
Continuous Casting Of Steel ◽  
Technological Parameters ◽  
Casting Method ◽  
Calculation Technique

The analysis of the performed researches has shown that the offered calculation technique is an effective means of management of formation process in casting. The found dependences and experimental data allow to calculate the specific value of the exactм heat flux in a given range of technological parameters obtained during a series of successful experiments for a particular casting method.Having the results of studies of the temperature regime of the mold during casting of a certain size and profile, it is possible to calculate the thermal state of the mold for the same casting process, but for the production of castings of any other size and profile.Having a certain amount of information on the temperature regime of the mold at different casting methods, you can use the solutions obtained to become the owner of a database containing the necessary information for solving the problems of solidification of the casting. In the subsequent design of equipment and equipment there is no need for additional experimental studies and analysis of the results.

scholarly journals FEATURES OF EXPERT RESEARCH ON THE EFFECTS OF LOCK PICK ON THE INNER SURFACES OF CYLINDER MECHANISMS OF LOCKS

2019 ◽  
Vol 20 (2) ◽  
pp. 292-308
Author(s):  
V. Chernov ◽  
Е. Golomisyuk ◽  
Р. Evseev
Keyword(s):  
Experimental Study ◽  
Experimental Studies ◽  
Design Features ◽  
Foreign Objects ◽  
False Conclusion ◽  
Internal Surfaces ◽  
Criminal Offenses ◽  
Trace Formation ◽  
Expert Study

The features of the expert study of traces from the effects of foreign objects on the inner surfaces of the cylinder mechanisms are considered. With the trasological examination of locks, most experts after examining the external and internal surfaces of the cylinder mechanisms of locks, unlocked by various types of keys, falsified or selected keys, ambiguously understand the mechanism of their trace formation, which can sometimes lead to a false conclusion. The purpose of the work is to present the results of the investigation of the mechanism of trace formation and localization of signs of exposure of foreign objects (lock pick, selected or fake keys) on the internal surfaces of the cylinder mechanisms of locks and recommendations to forensic experts in drawing conclusions during the course of the Trasological research. The mechanism of trace formation is considered, the characteristic and classification of traces of exposure to foreign objects are provided (lock pick, selected or fake keys). Groups of lock pick are identified, which are most often found in the Commission of criminal offenses, for their further research. A number of experimental studies have been carried out to study and analyze the mechanism of trace formation, as well as to localize the signs of influence of certain groups of lock pick on the internal surfaces of the cylinder mechanisms of the lock. The progress of the experimental studies has been described in stages. The results of the research on the opening of the cylinder mechanisms of locks are presented with various types of lock pick, depending on their design features. The illustrations explain the conditions for the location of traces on the relevant parts of the cylinder mechanisms of locks from the influence of the respective groups of lock pick. The results of an experimental study are summarized and conclusions are made on the possible conditions for the mechanism of trace formation. Recommendations to judicial experts on the formulation of conclusions in the course of trasological studies of cylinder locking mechanisms are proposed.

scholarly journals INFLUENCE OF CONSTRUCTIVE AND TECHNOLOGICAL PARAMETERS OF THE UNIT FOR STRIP TILL ON THE LUMPINESS

2020 ◽  
Author(s):  
G. Golub ◽  
◽  
A. Dvornyk
Keyword(s):  
Winter Wheat ◽  
Relative Position ◽  
Experimental Studies ◽  
Movement Speed ◽  
Technological Parameters ◽  
Depth Of Processing ◽  
Processing Depth ◽  
Economic Methods ◽  
Strip Tillage

The goal of the work. Investigate the influence of the relative position of the depth of processing with a chisel, the speed of movement of the unit and the distance between the cutting side discs on the lumpiness of the processed strip. Methods of research: analytical - quantitative determination of the quality of strip tillage; laboratory-field - for research, an experimental installation was completed with an MTZ-892 tractor and a section of the unit for strip tillage; statistical with generally accepted agronomic and economic methods. Results. Experimental studies of changes in the design and technological parameters of the unit for strip processing with the determination of lumpiness have been carried out. To study the main parameters, the depth of processing of the subsoiler (chisel) is taken from 13 to 27 cm, the distance between the cutting side discs is from 10 to 30 cm, the speed of the MTA is from 4 to 11 km/h. Unchanged parameters during the study: the distance from the axis of the front disc to the chisel is 50 cm, the distance from the chisel to the axis of the cutting side discs is 50 cm, the immersion depth of the cutting side discs is 10 cm. Experimental background is winter wheat stubble. Soil cultivation for winter wheat - deep (18 cm) disking, before that plowing to a depth of 25 cm. According to the research results, graphs of the dependence of lumpiness on the relative position of the chisel, cutting side discs and changes in the speed of the MTA were built. As the speed and distance between the side cutting discs increase, the lumpiness value decreases. Conclusions. Based on the results of the studies, the dependences of lumpiness on the relative position of the chisel and cutting side disks were obtained when the speed of the MTA was changed. It was determined that with an increase in the processing depth, the distance between the cutting side discs of 20 cm and the MTA movement speed of 7.5 km / h, a uniform increase in lumpiness is observed. The distance between the side cutting discs of 10 cm is not suitable for work.

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