- TITLE:
FINITE ELEMENT SIMULATIONS OF STATIC MECHANICAL SURFACE TREATMENT PROCESSES - A REVIEW AND PROSPECTS
- AUTHOR(S):
V. P. Dunchev, M. D. Ichkova
- ABSTRACT:
This article reviews finite element (FE) simulations of static mechanical surface treatment (MST)
processes for metal components. These static burnishing methods, based on severe plastic
deformations of the surface and subsurface layers, improve the surface integrity (SI) of the respective
components dramatically and thus their operational properties. The finite element method (FEM) is
a basic method used for numerical investigations of MST processes. Although FEM always requires
experimental verification and an experiment to establish an adequate material constitutive model,
this method saves the researcher significant time and resources. In this article, a comprehensive
analysis of the published studies devoted to FE simulations of static MST processes has been
conducted. Based on the analysis, five basic conditions have being established in order to build an
adequate FE model of the static burnishing process
- PAGES:
14-
- DOWNLOAD:
FINITE ELEMENT SIMULATIONS OF STATIC MECHANICAL SURFACE TREATMENT PROCESSES - A REVIEW AND PROSPECTS
- TITLE:
MATHEMATICAL MODELING OF WORKING PROCESSES IN A LIQUID-MAGNETIC DAMPER
- AUTHOR(S):
I.V. Nochnichenko*, O.S. Haletskyi, D.V. Kostiuk, S.V. Strutynskyi
- ABSTRACT:
A mathematical model of the workflow has been developed, which made it possible to study the
influence of design and geometric parameters, and also the influence of the working fluid
temperature on the performance of a hybrid liquid-magnetic damper. The combination of an
innovative hybrid structure, magnetic field and hydraulic throttling in the damper gives it new
properties, however, during development, arises the problem of choosing rational parameters of its
elements to ensure a given operating characteristic. To solve the problem posed, we analyzed the
physical processes occurring during the operation of the damper and built a mathematical model
using a cyclic-modular approach. Based on the results of mathematical modeling, a prototype of a
liquid-magnetic damper was made.
- PAGES:
91-
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MATHEMATICAL MODELING OF WORKING PROCESSES IN A LIQUID-MAGNETIC DAMPER
- TITLE:
MATHEMATICAL MODELING OF DYNAMIC PROCESSES OF THE TERRESTRIAL ROBOTIC COMPLEX MANIPULATOR
- AUTHOR(S):
S. Strutynskyi, R. Semenchuk
- ABSTRACT:
The calculation scheme, that allow to investigate dynamic processes of the manipulator of the
terrestrial robotic complex is offered. The dependences describing dynamics of the manipulator are
received. A dynamic model of the manipulator has been developed. This model takes into account the
possibility of using controlled damping devices. The obtained results take into account the influence
of variable external factors on the dynamic processes of the ground-based robotic complex. The
mathematical model of the manipulator can be combined with the existing mathematical model of the
chassis. The proposed mathematical model has practical value and can be used in the development
of a mechatronic system for stabilizing the position of the manipulator of the terrestrial robotic
complex.
- PAGES:
9-
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MATHEMATICAL MODELING OF DYNAMIC PROCESSES OF THE TERRESTRIAL ROBOTIC COMPLEX MANIPULATOR
- TITLE:
INTENSIFICATION OF TRANSFER PHENOMENA IN TECHNOLOGICAL PROCESSES DUE TO THE USE OF CAVITATION IMPACT
- AUTHOR(S):
I. Nochnichenko, O. Jakhno, K.Lugovska
- ABSTRACT:
The article deals with the cavitation process from the perspective of the transfer phenomenon.
For the first time, an attempt was made to link two physical processes - cavitation and the transfer
phenomenon. As a result, new opportunities open up for the intensification of working processes in
cavitation devices and, as a consequence, the possibility of deep control of the operating
characteristic of the system. It is shown that taking into account the transfer phenomena and
accompanying processes depends on the state of the liquid and is determined by the transfer
coefficients (viscosity, density, pressure). The processes in the cavitation apparatus of the
hydrodynamic type are experimentally investigated, the mechanism of intensification is proposed, the
regularities of mass transfer in liquid media under conditions of hydrodynamic cavitation are
studied. The influence of ultrasonic cavitation on the process of electrolysis of a liquid medium has
been investigated. The comparison of the obtained results of visualization with experimental
dependences is carried out
- PAGES:
8-
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INTENSIFICATION OF TRANSFER PHENOMENA IN TECHNOLOGICAL PROCESSES DUE TO THE USE OF CAVITATION IMPACT
- TITLE:
INFLUENCE OF THE INITIAL STEAM PARAMETERS ON THE OPERATION EFFICIENCY OF THE SHIP UTILIZATION TURBINE
- AUTHOR(S):
V. Aftaniuk* , B. Garagula, S. Aboleshkin, Y. Korovaichenko
- ABSTRACT:
The search for technical solutions aimed at improving the reliability of marine steam turbines
(including exhaust-driven turbines), which have a part of the expansion process in the two-phase
zone (wet steam), is an important issue in the operation of marine power plants. To date, not all
practically important tasks of two-phase mechanical environments are fully resolved. Questions of
optimization of lattices and shapes of flowing parts of the turbines working on water charged steam
remain open. No less important in this regard is the correct choice of parameters and the distribution
of heat differences by stages of the turbine. Research work in the field of water charged steam
turbines shows the need to develop specific recommendations for the most efficient (in terms of
energy loss and erosion wear of the blades) their operation. The purpose of this study is to develop
recommendations for the optimal choice of parameters of the stages of steam turbines running on wet
steam. The results of the analysis of the influence of the initial steam pressure in the last stages of
wet-steam ship turbines allows to avoid unfavorable (in terms of final humidity) operating modes and
thus increase their efficiency and erosion reliability. The most economical mode of operation for
recycling steam turbines that use low-potential heat of exhaust gases and operate in the field of wet
steam with a significant level of humidity is the mode in which the steam pressure at the inlet of the
turbine is about 0.7 MPa. An increase of this pressure leads to a significant increase of humidity
and, consequently, a decrease in efficiency. Reducing the pressure by less than 0.6 MPa significantly
affects the efficiency of the turbine due to the reduction of the available heat transfer, which makes
the use of exhaust-driven turbines impractical.
- PAGES:
7-
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INFLUENCE OF THE INITIAL STEAM PARAMETERS ON THE OPERATION EFFICIENCY OF THE SHIP UTILIZATION TURBINE
