- TITLE:
RESEARCH OF THE PHENOMENON OF HYDRODYNAMIC LUMINESCENCE IN A TWO-PHASE ENVIRONMENT
- AUTHOR(S):
V. Kryvosheiev, I. Nochnichenko, I. Liberatskyi
- ABSTRACT:
The article presents the results of the study of the phenomenon of hydrodynamic luminescence in
a two-phase medium during cavitation in hydraulic systems.
To conduct an experimental study, an analysis of the literature on the subject of the study was
conducted, a stand based on a hydrodynamic cavitator with an ejector mixer at the inlet was
developed.
The experiment was performed using mineral oil as a working fluid at an inlet pressure of up to 4
MPa and a flow rate of up to 10 -5 m3/s. The main parameters that were monitored: inlet pressure
level, inlet and outlet pressure drop of the sample, flow rate and outlet temperature. Shooting of the
processes occurring inside the model was carried out by the camera at a speed of 120 ... 1000 frames
per second. Cavitation areas were detected by high-speed video recording and the mechanism of its
development in a two-phase medium was studied.
As a result of the experiment, it was found that without saturation with inert gas, luminescence
occurs when the pressure drops by 2 MPa, whereas with the help of a gas mixture (with a
predominant inert gas content) when the pressure drops by 1 MPa.
It is concluded that the phenomenon of hydroluminescence can be used as a method for
visualizing cavitation. It was found that the saturation of a liquid with an inert gas affects the
rheological properties, namely: viscosity, density and physicochemical properties. The modes of the
appearance of the glow were determined separately for each component of the experiment.
- PAGES:
29-
- TITLE:
CAVITATION IN TECHNOLOGICAL PROCESSES
- AUTHOR(S):
J. Stryczek, O. Luhovskyi, O. Jakhno, D. Kostiuk, A. Murashchenko
- ABSTRACT:
The paper considers the phenomenon of cavitation observed in various types of technological
equipment. The nature of the appearance of ultrasonic and hydrodynamic cavitation and the factors
accompanying it is analyzed. It is shown that these two types of cavitation have been successfully
used to improve the quality of technological processes. The results of an experimental study of the
effect of cavitation on the physicochemical and rheological properties of a liquid are presented. At
the same time, both positive effects accompanying cavitation and undesirable phenomena are
considered, for example, in a number of machines and devices in chemical technology, for example,
the emergence of hydrodynamic cavitation in a closed volume of a gear pump is revealed. Designs of
devices for cavitation treatment of liquids are considered.
- PAGES:
21-
- TITLE:
NEW CONCEPT OF A HYBRID THERMOPLANE WITH A ROTATION BALLONETET
- AUTHOR(S):
O. Salenko, P. Pavlik, A. Gavrushkevich O.Samoilenko, O. Sulima, V. Shchetynin
- ABSTRACT:
This study gives the possibility of returning to the use of aircraft lighter than air. Hybrid aircraft
can improve the performance of traditional airships. For this, a comparison was made of the main
indicators of the main types of aircraft, which differ in the method of creating lift from each
other.This suggests that this type of aircraft using modern materials and technologies can be re-used
in modern aviation.
The paper considers the use of modern thermal insulation materials in the concept of an aircraft
using hot air as a working fluid. It is recommended to use aerogel to store the energy of heated
air.The use of aerogel as a heat-insulating material requires the study of heat exchange processes in
the thermal ballonetet. Some intermediate results obtained as a result of computer simulation are
presented in this paper and are descriptive.
- PAGES:
11-
- TITLE:
AUTOMATION OF MACHINES FOR PROCESSING OF AMBER BALLS AS JEWELRY
- AUTHOR(S):
Y. Kuznietsov
- ABSTRACT:
The purpose of the work is creation of productive automatic machines for grinding amber beads
with minimal costs for its manufacture and expluatation, providing high quality through parallel
processing of the rocker, modal principle, the active control and computer control.
- PAGES:
1-
- TITLE:
DESIGN OF SYNCHRONIZATION SCHEMES WITH IDENTICAL, ANTI- AND HYBRID SYNCHRONIZATION FOR A FIFTH-ORDER CHAOTIC MODEL
- AUTHOR(S):
D. Chantov, H. Stoycheva
- ABSTRACT:
The subject of this paper is the design of chaotic synchronization schemes with different types of
synchronization for a fifth-order chaotic model. Chaotic systems are a specific class on nonlinear
systems with complex dynamics, which are extremely sensitive to the initial conditions and possess a
strange attractor in the state space, consisting of infinite number of unstable periodic orbits. Two or
more such systems can synchronize their chaotic behavior, if a suitable control function is designed
and applied to them. These tasks are very popular research field in the last two decades, because
synchronized chaotic systems can be used for data protection in secure communication systems or
for file encryption. In this paper, chaotic synchronization schemes with identical synchronization,
with anti-synchronization and with hybrid synchronization are designed on the basis of a fifth-order
chaotic model. The control functions are calculated using the Lyapunov’s second stability method.
- PAGES:
10
