scholarly journals Energy analysis of transfer processes and their main characteristics in thermo mechanical damping systems

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Ihor Nochnichenko ◽  
Oleg Jakhno
Keyword(s):  
Energy Dissipation ◽  
Energy Balance ◽  
Total Energy ◽  
Shock Absorber ◽  
Energy Analysis ◽  
Mechanical Energy ◽  
Similarity Criteria ◽  
Conservation Of Energy ◽  
Transfer Processes ◽  
The Law

The article discusses the energy analysis of transfer processes in the damping system. The basic theoretical foundations based on the equations of the energy balance of the hydraulic shock absorber and the law of conservation of energy are presented. The proposed approach is associated with the development of a methodology and scheme for calculating the technical system of vibration damping. The schemes of interaction of the system through the phenomena of transfer and functioning of the vibration protection system with the environment are presented. It is shown that damper systems are based on the physical process of transformation of mechanical energy into thermal energy with subsequent dissipation into the environment. The total energy distribution in damping problems takes the following form the mechanical energy of motion is absorbed due to the hydraulic resistance of the liquid and turns into a dissipative component, which can reach 80% of the total energy. A mathematical model of the law of conservation of energy is presented which includes a dissipative function. The analysis of how it is possible to design work processes in a shock absorber due to energy dissipation and similarity criteria: Euler, Froude, Reynolds, etc. As a result of physical experiments, it was found that the movement of a fluid in hydraulic calibrated throttles gives rise to cavitation and various physical phenomena and accompanying processes, in which there is a significant change in the energy balance and energy dissipation in non-stationary modes of fluid movement. The dependence of the total power loss of the shock absorber under changing operating conditions, and the diagram of physical processes and energy transformations in the problems of damping, which are in dissipative processes, are given. The article describes the principles that can be used for the design of devices and modules of damper systems of a wide class with the possibility of energy recovery and accumulation by introducing a damper into the system, for example, a motor generator, an inductor with permanent magnets or a peso element in the design of a traditional telescopic shock absorber.

Technical condition of agricultural machinery

2021 ◽  
pp. 53-61
Author(s):  
A. A. Solomashkin ◽  
M. N. Kostomakhin
Keyword(s):  
Energy Balance ◽  
Object Oriented ◽  
Technical Condition ◽  
Object Oriented Programming ◽  
Agricultural Machinery ◽  
Working Capacity ◽  
Conservation Of Energy ◽  
Basic Functions ◽  
The Law ◽  
Expanded Concept

Two basic functions of the machine, consumer and technical are given. Application the law of conservation of energy is shown in case of the description of an energy balance of an element of the machine. The expanded concept of technical condition in relation to the machine is this, parameters of technical condition are justified. Communications of technical condition with operability and working capacity and also communication of operability of an element of the machine with its efficiency are defined. The possibility of representation of technical condition in the form of сlass in object-oriented programming is revealed.

scholarly journals The series elastic shock absorber: tendon elasticity modulates energy dissipation by muscle during burst deceleration

2015 ◽  
Vol 282 (1804) ◽  
pp. 20142800 ◽  
Author(s):  
Nicolai Konow ◽  
Thomas J. Roberts
Keyword(s):  
Energy Dissipation ◽  
Shock Absorber ◽  
Mechanical Energy ◽  
Reaction Force ◽  
Drop Height ◽  
Fascicle Length ◽  
Tendon Mechanics ◽  
Rapid Adjustment ◽  
Relationship Of ◽  
Tendon Compliance

During downhill running, manoeuvring, negotiation of obstacles and landings from a jump, mechanical energy is dissipated via active lengthening of limb muscles. Tendon compliance provides a ‘shock-absorber’ mechanism that rapidly absorbs mechanical energy and releases it more slowly as the recoil of the tendon does work to stretch muscle fascicles. By lowering the rate of muscular energy dissipation, tendon compliance likely reduces the risk of muscle injury that can result from rapid and forceful muscle lengthening. Here, we examine how muscle–tendon mechanics are modulated in response to changes in demand for energy dissipation. We measured lateral gastrocnemius (LG) muscle activity, force and fascicle length, as well as leg joint kinematics and ground-reaction force, as turkeys performed drop-landings from three heights (0.5–1.5 m centre-of-mass elevation). Negative work by the LG muscle–tendon unit during landing increased with drop height, mainly owing to greater muscle recruitment and force as drop height increased. Although muscle strain did not increase with landing height, ankle flexion increased owing to increased tendon strain at higher muscle forces. Measurements of the length–tension relationship of the muscle indicated that the muscle reached peak force at shorter and likely safer operating lengths as drop height increased. Our results indicate that tendon compliance is important to the modulation of energy dissipation by active muscle with changes in demand and may provide a mechanism for rapid adjustment of function during deceleration tasks of unpredictable intensity.

The technical condition of the machine, its serviceability and performance

2020 ◽  
pp. 33-42
Author(s):  
A. A. Solomashkin ◽  
M. N. Kostomakhin ◽  
K. G. Sovin
Keyword(s):  
Energy Balance ◽  
Object Oriented ◽  
Technical Condition ◽  
Object Oriented Programming ◽  
Technical State ◽  
Conservation Of Energy ◽  
Machine Element ◽  
The Law ◽  
And Performance ◽  
The Relationship

Two main functions of the machine are given, consumer and technical. The application of the law of conservation of energy in describing the energy balance of a machine element is shown. An extended concept of the technical condition is given in relation to the machine, the parameters of the technical condition are substantiated. The relationships between the technical condition and serviceability and serviceability, as well as the relationship between the serviceability of a machine element and its efficiency, have been determined. The possibility of representing a technical state in the form of a «Class» in object-oriented programming is revealed.

scholarly journals Energy balance formation of sub-eutectoide fayalita at high pressures in particle separators

Athenea ◽  
2022 ◽  
Vol 2 (6) ◽  
pp. 28-42
Author(s):  
Alberto Echegaray
Keyword(s):  
Energy Balance ◽  
Chemical Engineering ◽  
High Pressures ◽  
Control Volume ◽  
Mechanical Energy ◽  
Water Injection ◽  
Solid Particles ◽  
Wash Water ◽  
Conservation Of Energy ◽  
Institute Of Technology

This article presents an approach to the problem of ceramic types adhesion, applying energy and matter balance to the established control volume (cyclone) with the use of mathematical formulas that are interrelated to develop mathematical calculations and establish a new mathematical model The first results are obtained by operating the energy balance considering the collision of particles, using the principle of conservation of energy, the first law of thermodynamics, in order to obtain information that allows describing the phenomena of thermoplasticity and creep, in the formation of adhesions, from a physicochemical and kinetic point of view, which will serve as the basis for understanding their effect. As a result, an energy value of 660 kJ / mol was obtained, sufficient energy to start the transformation of the solid particles to a state of thermo-flow that allows the adhesion phenomenon to be started. Keywords: Adhesion, energy balance, cyclones, elutriation, eutectoid, fayalite, thermoplasticity. References [1]O. Bustamante. “Dissipation of mechanical energy in the discharge of a hydrocyclone”. (Dyna, Ed.) The network of Scientific Journals of Latin America, the Caribbean, Spain, and Portugal, vol. 80 (181), Pages 136-143, 2013. [2]K.Petersen, P.Aldrich, and D.Van.,”Hydrocyclone underflow monitoring using image processing methods. Minerals Engineering”, pp. 301-315,1996. [3]M. Farghaly,” Controlled Wash Water Injection to the hydrocyclone underflow” [Ph.D. Thesis]. Erlangen, FAU, 2009. [4]M, Schneider, and T. Neesse. “Overflow-control system for a hydrocyclone battery. Int. J. Miner. Process". 74, pp. 339 – 343, 2004. [5]J.Bergström., “Flow field and fiber fractionation studies in hydro cyclones” [Ph.D. Thesis] Stockholm, Sweden, Royal Institute of Technology, 2006. [6]C, Liu, L. Wang, and Q. Lui., “Investigation of energy loss mechanisms in cyclone separators”. Chemical Engineering Technology 28, pp. 1182-1190, 2005. [7]O.Dam. & E.Jeffes.,.”Model for detailed assessment of chemical composition of reduced iron ores from single measurement”. Ironmaking and Steelmaking, 1987. [8]E. Ringdalen., “Softening and melting of SiO2 an important parameter for reactions with quartz in Si production” pp 43-44, 2016.

scholarly journals Research of the mixing process in vortex static type devices

2019 ◽  
Vol 298 ◽  
pp. 00069
Author(s):  
Vitaliy Afanasenko ◽  
Petr Kulakov
Keyword(s):  
Energy Analysis ◽  
Mechanical Energy ◽  
Mixing Process ◽  
Direct Flow ◽  
Component Mixture ◽  
Flow Energy ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Two Component ◽  
Geometrical Dimensions

Mixing in chemical technology is used to intensify chemical and heat-mass transfer processes, as well as for preparing emulsions, suspensions and obtaining homogeneous systems. The simplest way to carry out the process, which does not require an additional supply of mechanical energy, is to mix in a direct-flow environment, which only requires flow energy. Analysis of the existing designs of direct-flow mixers showed that the use of swirling devices of various types in order to increase the efficiency of the process is very promising. This article describes a study of the influence of the geometrical dimensions of the screw on the efficiency of mixing a two-component mixture using the FlowVision software package.

Energy dissipation rate in a baffled vessel with pitched blade turbine impeller

1991 ◽  
Vol 56 (9) ◽  
pp. 1856-1867 ◽  
Author(s):  
Zdzisław Jaworski ◽  
Ivan Fořt
Keyword(s):  
Energy Dissipation ◽  
Cross Sections ◽  
Mechanical Energy ◽  
Vessel Diameter ◽  
Energy Dissipation Rate ◽  
Mean Velocity ◽  
Agitated Vessel ◽  
Radial Profiles ◽  
Pitched Blade Turbine ◽  
Turbine Impeller

Mechanical energy dissipation was investigated in a cylindrical, flat bottomed vessel with four radial baffles and the pitched blade turbine impeller of varied size. This study was based upon the experimental data on the hydrodynamics of the turbulent flow of water in an agitated vessel. They were gained by means of the three-holes Pitot tube technique for three impeller-to-vessel diameter ratio d/D = 1/3, 1/4 and 1/5. The experimental results obtained for two levels below and two levels above the impeller were used in the present study. Radial profiles of the mean velocity components, static and total pressures were presented for one of the levels. Local contribution to the axial transport of the agitated charge and energy was presented. Using the assumption of the axial symmetry of the flow field the volumetric flow rates were determined for the four horizontal cross-sections. Regions of positive and negative values of the total pressure of the liquid were indicated. Energy dissipation rates in various regions of the agitated vessel were estimated in the range from 0.2 to 6.0 of the average value for the whole vessel. Hydraulic impeller efficiency amounting to about 68% was obtained. The mechanical energy transferred by the impellers is dissipated in the following ways: 54% in the space below the impeller, 32% in the impeller region, 14% in the remaining part of the agitated liquid.

Conservation laws

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Dynamical System ◽  
Angular Momentum ◽  
Conservation Laws ◽  
Total Energy ◽  
Superposition Principle ◽  
Momentum Conservation ◽  
Conserved Quantities ◽  
Angular Momentum Conservation ◽  
Third Law ◽  
The Law

This chapter defines the conserved quantities associated with an isolated dynamical system, that is, the quantities which remain constant during the motion of the system. The law of momentum conservation follows directly from Newton’s third law. The superposition principle for forces allows Newton’s law of motion for a body Pa acted on by other bodies Pa′ in an inertial Cartesian frame S. The law of angular momentum conservation holds if the forces acting on the elements of the system depend only on the separation of the elements. Finally, the conservation of total energy requires in addition that the forces be derivable from a potential.

scholarly journals Hydrodynamic constraints on the energy efficiency of droplet electricity generators

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Antoine Riaud ◽  
Cui Wang ◽  
Jia Zhou ◽  
Wanghuai Xu ◽  
Zuankai Wang
Keyword(s):  
Energy Efficiency ◽  
Kinetic Energy ◽  
Total Energy ◽  
Viscous Dissipation ◽  
Shear Force ◽  
Mechanical Energy ◽  
Electric Energy ◽  
The Past ◽  
Viscous Shear ◽  
Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

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