Vol 10, No 1 (2011)

A method of determining heat exchange parameters of the aircraft hydraulic system units and pipelines has been developed and investigated. A model of the real unit heat exchange has been constructed and formulas for the calculation of heat-transfer coefficients of the unit and pipeline are proposed.

The paper deals with the problem of creating an optimal program of controlling low-thrust spacecraft in the flight between noncoplanar elliptical and geostationary orbits. A scheme for the joint change of orbital elements within the simple structure of the thrust vector control on the orbit turn is suggested.

Laws of distribution are established and numerical characteristics of selective numerical indexes for the process reproducibility are obtained. Positive displacement of the estimations accepted in the operating standards is revealed and compensated. More efficient unbiased are proposed.

The main problem of the article is the optimization of business processes with the help of SADT technologies using activity based costing method.

This study presents the numerical investigation of the behaviour of ball bearing 35-2310118E3C1 and its ability to work in helicopter transmission. A simplified mathematical model of transmission with ball bearings on rubber supports has been developed. The model was constructed taking into account the interaction between the cage and rings. The contact durability of bearing rings is calculated on the basis of "basic forces" and textolite cage rivet lifetime. Maximum allowable disbalances and vibratory velocities of transmission elements have been set depending on the cage rivets lifetime. Recommendations to increase the rivets lifetime are given.

Combination of the sol-gel technique, which allowed us to obtain fine-dispersed, homogenious, active starting system Ta2O5 - C, and carbothermal synthesis under vacuum resulted in nano-sized tantalum monocarbide synthesis at a relatively lowtemperature of 1200±50°C. The obtained product was investigated by means of XRD-analysis and transmission electron microscopy. The average size of TaC particles is 20-40 nm, the size of crystallites (calculated by the Sherrer method) is 4-8 nm.

The paper deals with the problems of determining optimal phase composition and structure, the proportion of phases of titanium alloys of mixed α-β and α structures, as well as the influence of heat treatment on the mechanical characteristics for providing improved characteristics of mechanical treatment and the quality of products.

Using the energy оf gas fuel differential pressure in electromagnetic injectors fоr improved breathing оf fuel-air mixture in cylinders by ejectiоn depends оn the chоice оf the place оf injectiоn, its directiоn and gas differential pressure in the injectors. A calculatiоn algоrithm is develоped оn the basis оf an elementary scheme fоr the оptimizatiоn оf these parameters. Its efficiency is estimated, and the results are cоmpared with the experimental data.

Analytical expression for the vector potential of a secondary electromagnetic field of two elliptical cylinders located in an alternating homogeneous magnetic field is obtained. Leontovich boundary conditions have been used in the process of deriving, with subsequent use of the boundary collocation method. The calculation of the vector potential amounts to the solution of a finite system of algebraic equations. The expression obtained makes it possible to simplify the calculation of the parameters being introduced, i. e. the parameters of eddy-current converters of displacement of samples having discontinuous surfaces.

A technique of operational monitoring of blade operational life exhaustion is proposed, based on the experimental data received with the help of discrete-phase movement transducers which use the discrete-phase method (blade tip timing).

The paper deals with the object-oriented approach to the creation of a system for the simulation of power objects, methods of representation of objects, their condition, properties, as well as ways of storage of these objects in an ordered way. It is shown how with the help of conventional functions in off-line systems of electrical power supply it is possible to solve design - analytical and directory problems. To solve the problems of controlling electrical engineering complexes, as well as for the automated management of static and dynamic information about the equipment and modes of its activity the information analytical system (1АС) "Pegas" is designed.

Proposed models of calculation of ionization current in semiconductor structures which arises under the influence of pulse radiating effect of gamma radiation are described. The current is defined taking into account the ambient temperature and the topology of elements of microcircuits, as well as the influence time. Besides, the effects of nonlinearity characteristic for the high dose capacity of gamma radiation are taken into consideration.

А model of public opinion competition in social and biological systems is introduced on the basis of the Vicsek model, which is an analog of the Ising model. The process of collective behavior formation in systems with two competitive groups of leaders is discussed. A program for computational investigation and visualization of transient processes in this model is developed. Characteristics that affect the quickness and the result of competition between two types of leaders are revealed. The parameter map of the number of individuals who remain beyond the leaders’ influence is drawn.

The paper presents the analysis of the industry’s current state and the efficiency of its functioning. The causes of low competitiveness of the products of Russian aircraft engine construction and the ways of dealing with the industry’s system crisis are analysed.