UDK 621.45.022 BBK 39.55

Skorobogatov S. V.

Isaev A. I.

With each passing year, the operational requirements for the aircraft power plants are getting stricter and stricter. The combustion chamber as one of the main parts of an aircraft engine determines the indicators of its efficiency, reliability and environmental compatibility. The indicators can be improved due to taking into account the operational requirements at the stage of designing a combustion chamber.

As the concept of a combustion chamber with a lateral system of reverse current area formation implies presence of a number of thin-walled elements as well as double-curved surfaces, designing a chamber of such construction is a complex engineering problem.

The article describes a technology of manufacturing a combustion chamber of the desired design on an example of experimental model for a chamber stand.

Key words: combustion chamber, aircraft gas-turbine engine, operational features, technology of manufacturing, combustion process.

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UDK 629.7.036.3 BBK 39.15

Kirenchev A. G.

Danilenko N. V.

The article considers the basic problems of vortex formation phenomenon and its natural and technogenic vortices. A new definition of vortex formation based on the physical essence of the working process is given. The mathematical foundation of the working process of vortex formation is presented with the use of Professor N. E. Zhukovsky’s theorem about the lifting force of the wing, as well as the equation for conservation of the gas movement energy and the Stokes theorem about the equality of the vortex tension and velocity circulation. Due to the analysis of the energy conservation equation the main factors of generation and accumulation of natural and technogenic vortices are revealed. The issue of the determining role of the underlying surface for forming effluent vortices of air intakes of aircraft gas-turbine propulsion systems is investigated. Influence of other external factors on the formation of technogenic vortices is noted. Classification of technogenic vortex formation and its vortices by the essence of the working process is given.

Keywords: vortex formation, technogenic vortices, vortex interference, the role of the underlying surface, gas turbine power plants, mathematical justification of Coriolis force vortices, air intake.

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UDK 621.438, 004.855 BBK З363.3, 32.813, 22.18

Novikova S. V.

Kremleva J. Sh.

The article presents a technique of increasing the robustness of a neural-net model of gas-turbine engine monitoring during stand tests due to decreasing the number of insignificant links in the neural network (neural network reduction). The technique is based on converting the problem of neural network learning into that of multi-criteria optimization which includes the error minimization criterion and the criterion of minimizing the absolute values of the weight links of a neural network. The latter requirement leads to reveal of insignificant links which can be deleted without any loss of accuracy. As a result, the ability of the model to summarize increases greatly, robustness increases as well, the calculation error of monitored parameters decreases.

Key words: model robustness, neural networks, stand tests, monitoring of a gas-turbine engine, reduction of a neural network.

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