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CONTENTS #7 (July) 2018

Vortex Mechanics of Laminar-Turbulent Transition (c. 3 – 6)

A.G. Prudnikov, A.M. Podvalnyy

The model of a laminar-turbulent transition is presented. Analytical solutions of the beginning and the end of a laminar-turbulent transition are given.

Keywords: vortex mechanics; vortex; boundary layer; laminar layer; turbulent layer; shock wave.



Analysis of Acoustic Emission Method Availability for Мi-8 Helicopter Structure Diagnostics in Flight (c. 7 – 13)

A.N.Seryeznov, L.N. Stepanova, S.I. Kabanov, E.Yu. Lebedev, V.L. Kozhemyakin, A.B. Kuznetsov

The destruction of Д16 duraluminium samples of 190×20×2 mm size in laboratory environment and under Ми-8 helicopter flight conditions with activated engines at the time of takeoff and hover. The samples were loaded statically with a hydraulic jack thruster up to des-truction. Two acoustic sensors were additionally installed on the frame of the helicopter. Re-gistration of information in real time was performed by certified acoustic-emission (AE) and strain-gage systems. During the flight of the helicopter, an analysis was made of the effect of engine noise and vibration of the helicopter structures on the detected AE signals.

Keywords: acoustic emission; strain measurements; helicopter; flight; sample; jack thruster; noises.



Method of Stress-Strain State for Structurally-Anisotropic Panels Made of Composite Materials with the Influence of Production Technology and General Boundary Conditions (c. 14 – 23)

L.M. Gavva, S.A. Lurie

The exact analytical solutions for edge problems recording general treatment of structure elements physical boundary conditions are considered. The new mathematical model relations for stress-strain state investigation of structurally-anisotropic panels made of composite materials are presented. The mathematical model of stiffening rib being torsion under one-side contact with the skin is refined. One takes into account the influence of panel production technology: residual thermal stresses and reinforcing fibers preliminary tension. The resolved eight order equation and natural boundary conditions are obtained with variation Lagrange procedure. The new method algorithm for solution as series with non-orthogonal system of general proper functions and analytically defined constants is given. Computer program package is developed using operating Matlab system. The influence of real contour restrictions on the level of stresses and displacements has analysed for un-centrically stiffened panel.

Keywords:panels made of composite materials; un-centric longitudinal and lateral set; thin-walled rib; non-symmetric package structure; force and technology temperature action; stress-strain state; general boundary conditions; uniform solution method.



Miniaturization of Spacecrafts: Development and Application of Small Satellites (c. 24 – 35)

K.G. Bomstein, V.Y. Granich

Analyzes the current state in the field of miniaturization of space technology, including the development of small satellites and the formation of the market of services using them.

Keywords: мiniaturization; minisat; microsat; nanosat; picosat; femtosat; launch.



Ensuring the Design Reliability of Unfolding Structures Spacecraft (c. 36 – 45)

A.A. Zolotov, Yu.P. Pokhabov, E.V. Gusev

Suggests a technique for selecting the design parameters of the disclosure facilities the deployable spacecraft designs. On the basis of the analysis of the process of functioning of the unfolding structures (US), a technique is suggested for taking into account the relationship between the safety factor adopted in traditional strength calculations and the safety factor in the disclosure of US at the initial stage of the design development.

Keywords: design parameters of disclosure facilities; reliability; unfolding structure; strength calculations.



Small-Sized Integrated Two-Band SAR for a UAV of Monitoring of an Ice Surface in the Arctic Region (c. 46 – 55)

O.V. Vasilyev, A.N. Detkov

The principles of creating a small-sized dual-band radar with a synthesized and integrated aperture of the X- and P-band antenna as the target load for an UAV providing operational air reconnaissance of the ice surface in the Arctic region are given.

Keywords: SAR; the two-band integrated antenna system; UAV; air reconnaissance; ice surface; radar image.



The Use of 3D-Simulation Programs in the Development and Finalization of the Main Combustion Chamber of a Gas Turbine Engine (c. 56 – 62)

A.B. Agulnik, V.R. Nelyubin, A.S. Pavlov

The application of the NX and ANSYS programs brought to a new level the design and finalization of the main combustion chambers in gas turbine engines. Since before the experiment it was possible to improve the performance (increase in the completeness of combustion, reduce the radial and circumferential unevenness of the total gas temperature), and also to determine the weak points of the structure in connection with the unrealistic installation of recording sensors pressure and temperature in some areas of the main chambers, due to the high temperature of the gas, and the averaged characteristics do not allow to localize the potential places of burnouts.

Keywords: main combustion chamber; gas turbine engine; a centrifugal nozzle; swirler; flame tube.



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