Визначення орієнтації на основі геометричних співвідношень

The algorithms of attitude determination based on geometric relations and least-squaresmethod is suggested. Comparison with algorithm QUEST is fulfilledПредложены алгоритмы определения ориентации твердого тела, базирующиеся на геометрических соотношениях и методе наименьших квадратовЗапропоновано алгоритми визначення орієнтації твердого тіла, які базуються на геометричних співвідношеннях та методі найменших квадраті

Induction surface hardening of 42CrMo4 steel tubes designed for rotary percussive drilling equipment

42CrMo4 steel tubes are subjected to multiple induction heat treatments to obtain various hardened layer depths after spray water quenching. Current frequency, induction unit power and coil movement velocity along the tube axis are under consideration. The hardened layer depth is estimated along the transverse direction of the tubes using metallographic studies and microhardness measurements. An empirical equation is obtained for the hardened layer depth as a function of the induction heat treatment parameters. The laboratory test results are employed to develop the technology of the production of 42CrMo4 steel tubes designed for rotary percussive drilling equipment. The service life of induction hardened tubes during abrasive wear resistance field tests is approximately twice as long as that of conventionally nitrided ones. © 2016 Author(s)

The dependency of mechanical properties on the microstructure anisotropy index of some alloyed steels

The microstructure banding of the 4340, 42CrMo4 and 20NC11 alloyed steels is estimated using the approach of the ASTM E 1268 standard. The values of the anisotropy index and microhardness are obtained on the longitudinal specimens at various distances from the center of round steel bars with various diameters. Impact strength values in the transversal and longitudinal directions of the bars are obtained. The correlation of the anisotropy index values and the mechanical properties (microhardness and impact strength) of the steels under consideration is derived. © 2017 Author(s).Research are carried out (conducted) with the financial support of the state represented by the Ministry of Education and Science of the Russian Federation. Agreement (contract) no 14.578.21.0114 27.10.2015. Unique project Identifier: RFMEFI57815X0114

Improving the impact toughness of the Hy-Tuf steel by austempering

The microstructure and mechanical properties of the high-strength Hy-Tuf steel are studied after different heat treatment modes - conventional oil quenching and tempering, austempering in the bainite transformation temperature range. It is shown that the tempering embrittlement of the Hy-Tuf steel can be observed at temperatures ranging between 400 and 500 °C. The highest impact toughness of the studied steel for the case of conventional oil quenching and tempering (1.2 MJ/m2) can be achieved after high temperature tempering (600 °C), which also leads to the deterioration of tensile strength down to 800...900 MPa. The unique combination of high tensile strength (above 1300 MPa), elongation (up to 15%) and impact toughness (1.1 MJ/m2) is obtained after austempering at a low transformation temperature. © 2018 Author(s)

Modeling of phase transformations in steel products during cooling process

Методика численного моделирования превращений в процессе охлаждения изделий из металлов и сплавов позволяет с технически приемлемой точностью прогнозировать структуру и свойства готовых изделий после того или иного вида термической обработки (нормализация, закалка и т.п.). Методика является универсальной, т.к. позволяет проводить расчеты по заданному алгоритму для изделий любой формы, сечения, изготовленных из любой марки стали и сплавов. В результате становится возможным для материала определенного химического состава установить параметры режима термообработки для получения необходимой структуры и эксплуатационных свойств готовых изделий без проведения дополнительных экспериментов.Numerical modeling of cooling process and phase transformations in steel parts allows technically accurate predicting of their structure and properties depending on the heat treatment sequence applied (normalization, quenching etc.). The method is universal, as it allows calculations for parts of different design, size and for any steel or alloy grade. As a result, it becomes possible to set optimal heat treatment parameters providing desirable structure and properties of finish products with given chemical composition without time / material consuming experiments.Программа развития УрФУ на 2013 год (п.2.1.2.1

Study of the two-stage gasification process of pulverized coal at the hydrodynamic flow separation

The paper presents a numerical study of advanced two-stage gasifier with a combined countercurrent and concurrent flow pattern and dry fuel feed system EAGLE. The Kuznetsk coal was used as a fuel for the gasifier under study. We have conducted studies on the influence of the inclination angle of the upper burners in horizontal and vertical planes, and the amount of steam supplied, on heat and mass transfer processes in the chamber as well as on the composition of coal-derived gases. It is shown that the increase in the inclination angle of the upper burners in the horizontal plane allows intensifying the process of two-stage gasification and makes it possible decreasing the height of the chamber without sacrifice of the composition of the coal-derived gases. © Published under licence by IOP Publishing Ltd.Problem statement (section 1 and 2) and results analysis (section 4) were carried out at UrFU and supported by the Russian Science Foundation by Grant 14-19-00524 (M. Chernetskiy and A. Ryzhkov

Shaken Granular Lasers

Granular materials have been studied for decades, also driven by industrial and technological applications. These very simple systems, composed by agglomerations of mesoscopic particles, are characterized, in specific regimes, by a large number of metastable states and an extreme sensitivity (e.g., in sound transmission) on the arrangement of grains; they are not substantially affected by thermal phenomena, but can be controlled by mechanical solicitations. Laser emission from shaken granular matter is so far unexplored; here we provide experimental evidence that it can be affected and controlled by the status of motion of the granular, we also find that competitive random lasers can be observed. We hence demonstrate the potentialities of gravity affected moving disordered materials for optical applications, and open the road to a variety of novel interdisciplinary investigations, involving modern statistical mechanics and disordered photonics.Comment: 4 pages, 3 figures. To be published in Physical Review Letter

Study of the two-stage gasification process of pulverized coal with a combined countercurrent and concurrent flow system

The paper presents a numerical study of an advanced two-stage gasifier with a combined countercurrent and concurrent flow pattern and dry fuel feed system EAGLE. The Reynolds Stress model was used for the numerical simulation of turbulent flow. We have conducted studies on the influence of upper burner's inclination angle on heat and mass transfer processes in the gasifier as well as on coal conversion. It is shown that the increase in the upper burner's inclination angle in the horizontal plane allows intensifying the process of two-stage gasification. © 2017 The Authors, published by EDP Sciences.Problem statement and results analysis were carried out at the Ural Federal University and financially supported by the Russian Science Foundation (project no. 14-19-00524). The development of methods for mathematical modeling and calculations was carried out with the financial support of the Ministry of Education and Science of the Russian Federation under the Grant Agreement No. 14.607.21.0150 (Unique identifier of the RFMEFI60716X0150

Vector methods for determination of rigid body orientation

Vector methods for determining the orientation of a rigid body using information about vectors in the reference and body-related coordinate systems are considered. The analysis is based on the least squares method in vector-matrix form. This approach allows us to consider the application of different methods of solving the problem from a single standpoint: matrix (using the directional cosine matrix), geometric (using the Gibbs vector), quaternion (using the quaternion of rotation). Numerical evaluation of the accuracy of eight orientation determination algorithms obtained on the basis of these methods was performed.Розглянуто векторні методи визначення орієнтації твердого тіла sз використанням інформації про вектори в опорній та повʼязаній із тілом системах координат. В основу аналізу покладено метод найменших квадратів у векторно-матричній формі. Такий підхід дозволяє із єдиних позицій розглянути застосування різних методів розв'язання задачі: матричного (з використанням матриці напрямних косинусів), геометричного (із використанням вектора Гіббса), кватерніонного (із використанням кватерніону повороту). Проведено чисельну оцінку точності восьми алгоритмів визначення орієнтації, отриманих на основі даних методів