2012. № 61

The method of short-term measurements in the stage of irregular thermal mode applied to the study of solids on the example of quartz glass. For obtaining values of heat physical characteristics of the studied bodies which have not been distorted by radiating transfer it is necessary to probe a temperature field only optically a translucent layer.

Keywords: heat conductivity, hot-wire technique, measurement, non-stationary heating, radiative heat transfer

Mechanical system consisting of a spacecraft, a weightless elastic tether and a payload is investigated in this paper. The spacecraft is considered as a rigid body, and the payload – as a material point. Chaotic motion of the spacecraft in case of a vertical tether and in case of the presence of small oscillations of the tether in neighborhood of steady radial state is compared. It is shown that existence of small oscillations leads to increasing of a chaotic layer thickness and to fuzzying of regular trajectories on Poincare's sections, but doesn't lead to quality change of a pattern received for the case of vertical tether. Motion of spacecraft in case of slack tether is studied. It is shown that existence of sections of the free motion of the tether and the payload leads to chaotization of spatial motion of the spacecraft.

Keywords: space tether system; circle orbit; chaos; bifurcation; Poincare's sections

Three dimensional non-stationary model of inductively coupled plasma torch for optical emission spectrometry was developed and experimentally tested. The processes of ignition and steady burning were considered. The effects of plasmoids formation and pulsations and rotation of the plasma jet were identified, experimentally confirmed and interpreted. Simulated results are in a good agreement with the experimental data obtained by Schlieren measurements.

Keywords: inductively coupled plasma, three dimensional non-stationary model, schlieren method

It is considers stochastic approach to aiming process in general, using variable structure of weapon control system. Quality indicators of aiming process was formulated. The general problem solution of aiming process analysis was considered, taking into account its dynamics and absorption and recovery implementations of Markov’s stochastic processes theory.

Keywords: aiming; weapon control system; system analysis

At this work the criteria of safety separation of aircraft loads with aid of aircraft armament installation from the aircraft carrier is determined. It is analyzed the maximum possibilities and control algorithms of single- and multi positioned systems of the forced separation of the aircraft armament installations with open-loop control system. It is proposed the scheme of adaptive system building of forced separation with the closed control circuit.

Keywords: aircraft armament installation; forced separation system; safety separation conditions; adaptive system; open-loop system; closed system

It is developed the mathematical model of functioning of the autonomous adaptive system on forced separation with feedback for the pusher moving speed which don’t require the information about acing outer forces at the aviation load. It is analyzed the influence of pyrotechnic device type on the moving parameters of separated aviation load.

Keywords: aircraft armament installation; adaptive system of forced separation; closed system; feedback; linear acceleration transducer; separation load safety from aircraft

In article two examples of use of the queueing theory for analytical modeling of operations and a estimation of efficiency of a combat helicopter system (CHS) in volume of a sortie combat are considered. The majority of the military operations developing on the scheme of «queueing», are casual processes which are not-Marcovian process. The method which allows to bypass this difficulty by means of transforming of a not-Marcovian process to the Markovian process and to use for research mathematical apparatus of the queueing theory is considered. The offered technique is rather universal for analytical modeling not only operations of helicopters, but also many other combat operations of aircraft which are modeling like of model of queueing.

Keywords: combat helicopter system; appearing (maneuvering) target; queueing system with limited time of stay of the demand in system; marked conditions graph; Markovian stochastic process; generalized flow of Erlanga; method of "pseudo-condition"; relative capacity; absolute capacity

In the given work aerodynamics characteristics calculations of flat plate profile were presented. Investigations on two calculating meshes, built with conditions, when fist site of the mesh in one cause is at the distance of h = 10^-5 of wing chord and in second cause is at the distance of h = 10^-4 of wing chord were carried out. The aerodynamic coefficients, calculated by this two meshes, are practically coincide is established.

Keywords: flat plate; calculating meshes; aerodynamic coefficients; numerical methods

The results of numeral design of type are presented with the declined wing flap and additional organ of management (by a corymb). Was a corymb set in the place of joint of type and wing flap on leeward part covered under the corner of relative chords of type δ=45°. The results of aerodynamic coefficients were got (Су_а, Сх_а, mz, K).

Keywords: additional organ of management (by a corymb); wing flap; numeral methods; aerodynamic coefficients; tearing away of stream

Main principles of modern steering gear dynamic characteristics limits determining are developed, using aircraft marginal flight modes, such as marginal overload and disposable roll rate. A new method of steering transmission mechanical characteristics calculating is presented.

Keywords: limit dynamic characteristics; steering; aircraft maneuvering; marginal overload

Principles of construction, construction scheme stationary aerometric combined receiver and algorithms processing of the primary information , measurement system of the wind vector parameters in the parking lot, while driving and maneuvering on the earth's surface, in the takeoff and landing and hovering single-rotor helicopter are considered.

Keywords: helicopter; starting and takeoff and landing modes; wind vector; parameters; measurement; system; construction principles; stationary aerometric combined receiver; algorithms processing of primary information

Presented are the mathematical and programming tools (MPT) to analyse the dispersion of the aircrafts (AC) fragments over the Earth surface with taking into account the atmospheric breaking and small perturbances of the initial velocity at the passive stage of trajectory (PST). The circular probilistic deviation (CPD) of the AC fragment falling point from an assumed nominal one which is defined without random perturbances is accepted as a performance index of the dispersion. It is shown by using the MPT in a model example that the CPD is increased very much for the nominal trajectories with low initial angles within the broad range of the spherical flight longitude.

Keywords: aircraft; the perturbed motion; the atmospheric breaking; the ballistic derivatives, баллистические производные; the circular probilistic deviation

The possibility of using space-based large scale laser system (based on the cw chemical HF laser) to protect the spacecraft against the impacts from space debris is shown. The most probable cases of space debris (that moves on elliptic orbits) approaching the spacecraft (that moves on circular orbits) are studied, such as when their orbits cross at certain angle or are located in the same plane. The technique of laser pulses impact on the space debris approaching the spacecraft is developed for the cases considered.

Keywords: space-based laser system, cw chemical HF laser, space debris, orbite elliptique, the true anomaly, pulse-periodic mode of laser radiation

The paper presents the results of experimental studies on friction factor and heat transfer in tubes with 2D- (obtained by rolling) and 3D- (obtained by stamping) discrete roughness for forced convection of water in the range of Reynolds number Re = 200 ÷ 100,000. Preliminary assessment of thermal-hydraulic performance data was done.

Keywords: surface intensifiers; dimples; ring rolling; thermal-hydraulic performance

In the article leads results of the tree-teeth labyrinth seal flow modeling obtained with ANSYS-CFX. The results were compared with experimental data acquired on test facility «Dynamic Seal Model». Experimental data allowed to compare measured pressure distribution along chambers and in circumference of the rotor in the chamber’s centers. Such integrated approach for verification of the modeling strategy and ANSYS-CFX permits more efficient using this software in engineering practice, seals design in modern gas turbine. Also it helps to find way to increase efficiency of the gas turbines through improving their dynamics. The article is useful for engineers specialized in aerodynamics and turbo-machinery.

Keywords: labyrinth seals; computational fluid dynamics

The authors propose intelligent cooling system of engine, which is providing high fuel efficiency and reducing of emissions.

Keywords: control system; pump; cooling system; efficiency

A method of designing a differential pressure sensor with capacitive-primary head with the use of computer simulation MATLAB. Proposed route design and standard design procedures for a class of pressure sensors in the simulation environment MATLAB, the development of basic electric circuits and printed circuit board pressure sensor method through designing in CAD Mentor Graphics, design development and implementation of verification calculations among Solid Works. For the investigation of the metrological characteristics of the primary differential capacitive pressure transmitter and test the adequacy of the model was made mock pressure sensor.    

Keywords: a technique of designing of the sensor of pressure; a designing route; simulation modeling in the environment of MATLAB; typical project procedures in a Mentor Graphics CAD; Solid Works

In this issue the results of mathematical and physical modeling of fiber-optic refractometric sensor based on π-shifted fiber Bragg grating are presented.

Keywords: fiber Bragg grating; π-shift; refractometry

Technical diagnosing, quantitative are estimated.Technical conditions, individual forecasting, ranging of the same objects on time of no-failure operation,are estimate.The recommendations for the person making decisions are considered.

Keywords: technical diagnosing; models of the states; technical conditions; individual forecasting; recommendations for the person making decisions

Complete numerical model of double-stage atomizer for analytical spectrometry was developed. It consists of graphite vaporizer and tungsten helix-shaped atomizer model. Our approach is based on the numerical solution of the Navier-Stokes equations and the molecular kinetics and takes into account both of heating by electric current, gas dynamics and unsteady heat transfer, as well as evaporation and condensation of substances’ atoms. Solution was validated with the help of prototype of helix-furnace atomizer specially developed for this purposes in our lab. The simulation results are in good agreement with experimental data.

Keywords: computational fluid dynamics; thermal decomposition of substances; atomic absorption spectroscopy; electrothermal atomization

The article deals with the numerical solution of the direct heat conduction problem by periodic heating of the sample using an anisotropic conductive thin film. Its solution is needed for determining the thermal properties of materials.

Keywords: thermal properties; computer modeling; materials

It is analyzed whether it is possible to estimate damage accumulation taking place in cantilever samples made of C-C composite material caused by vibration testing by means of observing how self-resonant frequency of the samples changes during test. References to previous results obtained for the samples made of stainless steel and other materials are given. The simplified variant for generating a strength surface for the composite material by using tensor-polynomial failure criterion is examined.

Keywords: structure materials; ion thruster electrodes; C-C composite material; lifetime; fail; vibration tests; modal characteristics; cantilever samples; tensor-polynomial failure criterion; strength surface

The state and prospects of innovation systems models development, initiated by enterprises-users, are reviewed in the article. Motivations to innovative enterprises activity were educed and the innovation instruments system was offered. The necessity of airlines direct participation is grounded for product/technologies innovative developments.

Keywords: airlines; innovations; users' developments; managerial contacts; innovative models