The article considers general approaches and modern monitoring systems for rotary machines of electric generating equipment. The main characteristics of monitoring and diagnostics systems of Russian ...and foreign manufacturers are presented. Modern trends in the construction of intelligent systems for analyzing the performance of turbo generators and predicting possible failures in order to minimize the cost of repairs and forced shutdown of equipment are outlined. The concept of adaptive-predictive use of rotary machines, the difference from existing systems is the presence of adaptive module that allows to react to unwanted changes in real time and increase the predicted residual resource or eliminate the predicted probability of initially refusal.
The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared ...spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm
−1
. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described.
New methods for non-destructive testing of diffusion coefficient in thin-sheet and massive products made of isotropic and anisotropic porous materials are considered. In contrast to the rigid ...structure in the known methods, the represented methods are more flexible in implementing measurement procedures due to higher accuracy of measuring the desired coefficient. Flexibility is provided by calculating experimental data in the preferred sections and by choosing there the static characteristic of the transducer with a stable and noise-proof output signal and in the ranges with high sensitivity to changes in parameters. Expressions for calculating the desired diffusion coefficient for each test subject and a generalized sequence of measurement procedures are introduced. The modified version of the information and measurement system for implementing the proposed methods is described, and the results of the research are presented.
The importance of jet noise for prospective supersonic transport (SST) in takeoff and climb modes dictates the need to develop methods for reducing jet noise and their subsequent validation in large- ...and full-scale tests. This paper presents the results of Russia’s first ground acoustic tests of a rectangular nozzle with a noise suppression system, installed on a subsonic aircraft engine to demonstrate the technology. The authors studied a rectangular beveled nozzle with an ejector and screens—elements of the SST airframe. The test results were compared for three nozzle geometries: a round nozzle corresponding to measurements for the original engine without modifications, a rectangular nozzle without screens, and a rectangular nozzle with screens. It was found that when the rectangular nozzle without screens is used, there two opposite effects occur: noise amplification compared to the round nozzle for angles of observation close to the jet axis, and noise attenuation at angles of observation close to the fan rotation plane. Installing screens increases noise up to 5 dB in the low-frequency region below 150 Hz and reduces noise by 2 dB for frequencies higher than 250 Hz. Estimation of community noise in the EPNL metric showed that this rectangular nozzle with the noise suppression system has the effect of reducing community noise in comparison with the baseline round nozzle.
Abstract
The article is devoted to the analysis of the effect of laser surface modification on the hardness and wear resistance of steel SHX15SG used in the manufacture of roller screw mechanisms. ...Experiments on laser surface modification were performed on the Russian domestic SVAROG-1-5DR laser system. to get the maximum hardness value. When laser processing without melting the surface of steel SHX15SG, the laser radiation power should be in the region of 5 kW, which corresponds to the maximum power for the installation used. The speed of movement of the laser beam relative to the treated surface should be equal to 25 mm/s, and the focal length should be at least 60 mm. In the case of laser treatment with surface reflow, higher hardness values are obtained at a power of 2 kW. Increasing the power of laser radiation to 5 kW leads to a decrease in hardness. In this case, the speed value should be equal to 25 mm/s, and the focal length should be close to 85 mm. When the focal length is reduced to 60 mm, laser treatment no longer causes melting of the surface of the material under study.
The noise of a modern regional aircraft was measured using the beamforming method during flight tests in the landing approach configuration with extended landing gear and deflected high-lift devices ...(slats and flaps). The localization and ranking of aircraft noise sources for full-scale Reynolds numbers has been carried out. Comparison of the flight test results with the results of acoustic measurements of airframe noise for a large-scale wing model obtained earlier at DNW-NWB showed good agreement between noise measurements of the large-scale model, scaled to full size, with the results for the airframe noise of an aircraft wing in flight tests.
•The composites with periodic and random arrangement of spheroidal particles are considered.•Effective conductivity of spheroidal particle composite with imperfect interfaces is studied.•The complete ...solution of the conductivity problem has been obtained by the multipole expansion method.•Combined effect of microstructure and interfaces on the effective conductivity of composite is evaluated.
The rigorous analytical approach to the conductivity homogenization problem for spheroidal particle composite with imperfect interfaces has been developed. The complete multipole series solution for a single inclusion with imperfect interface constitutes mathematical background of the work and provides a basic building block for the Maxwell and Rayleigh homogenization schemes. The low- and highly conducting spheroidal interface are considered in a unified way. The developed theory enables an analysis of composites of periodic and random micro structure with imperfect interfaces. Numerical study shows quite a significant combined effect of micro structure and imperfect interfaces on the macroscopic conductivity of composite. The obtained accurate solution serves as a benchmark for the known approximate theories. Their error due to neglecting the interaction effects and simplified treating the imperfect interfaces is estimated.
The paper presents data on the influence of the direct sowing technology on the soil water regime, the yield and the grain quality of the spring wheat in the steppe zone of Altai Krai. The results ...showed that 2009 was the best year for the spring wheat yield; 2012, 2014 and 2015 were characterized by the minimum values of the soil moisture content and the spring wheat yield. However, there was the highest amount of gluten in grains during these years. The correlation between the yield and the water accumulation in the meter soil layer for the autumn-spring period was the highest, R=0.83. This can be taken into account in the direct sowing technology implementation in the spring soft wheat production.
PDF
