Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет

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Автор: search.filters.author.Yershina Ainagul

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    Тип записи:Публикация,
    PROTECTION OF ROTARY TYPE WIND AGGREGATES IN UNFAVORABLE CLIMATIC CONDITIONS
    (2009-01-01)
    A.K. Yershina
    ;
    Chingiz Yershin
    Transfer to alternative sources of energy is becoming a worldwide trend and is realized with wide political support of many countries like in Republic of Kazakhstan. In this case, the problem of using energetic equipment in unfavorable climatic conditions rises. Below, we consider how this problem is solved on an example of wind-driven electric plant (WDEP) in Kazakhstan. The working of WDEP in Northern, Central and Eastern Kazakhstan is fraught with serious consequences. There are frequent days with long snow storms (blizzards), which results in a wet snowdrift on open surface devices with formation of tightly snow-ice shell. Researches done during the last 12 years at the department of mechanics of the Kazakh national university (al-Farabi), allowed developing rotary type wind aggregates with working blades such as the alary NASA-0021 type [1] which includes the working by heat protection of the rotating elements which allows maintaining them in dry and warm conditions in any unfavorable climatic conditions.
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    Тип записи:Публикация,
    Definition of aerodynamic characteristics wind turbine to Darrieus of system troposcino
    (Al-Farabi Kazakh National University, 2016-01-01)
    Sh. A. Ershin
    ;
    A.K. Yershina
    ;
    Rustem Manatbayev
    ;
    A. K. Tulepbergenov
    Recently the majority show interest in connection with a number of merits to vertically-axial wind turbine type to Darrieus. It is possible to tell that age such wind energy installations of 25-30 years whereas others types wind turbine (sailing, propeller) have seriously started to study almost 1,5 centuries. The theory of these wind turbine with sufficient completeness are resulted in known E. M.Fateyev's monograph. In the present to article results of a theoretical substantiation for one of design kinds wind turbine are stated Darrieus - systems troposcino. This constructive form of the device to Darrieus becomes more and more popular. The general theory is constructed, almost all constructive and aerodynamic characteristics (linear speed, carrying power, front resistance are defined; wind power operating ratio; the moment of rotation of the turbine ) this device. Thus, attempt to put basic bases of the theory of devices to Darrieus of system troposcino is made. This report shows main theoretical principles of troposkino wind-turbine. Theoretically were determined dynamical characteristics of the wind-turbine, such as: rotation moment, power, useful wind energy coefficient and physical model of the plant. The theoretical results were compared with well-known experimental data.
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    ДВУХРОТОРНЫЙ ВЕТРОЭНЕРГЕТИЧЕСКИЙ АГРЕГАТ НВІ-РОТОР С ВЕРТИКАЛЬНОЙ ОСЬЮ ВРАЩЕНИЯ
    (2021-04-27)
    A.K. Yershina
    ;
    А. Н. Карымбай
    Climate change is one of the most widely discussed issues in the world today. This problem is devoted to publications in Newspapers and magazines, television reports, discussions of scientists, speeches of politicians. The transition to renewable energy sources is a global process and is being implemented with broad political support from many countries, including the Republic of Kazakhstan. The article deals with the use of wind energy in Kazakhstan and the characteristics of the designs of the new version of the Darrieus wind turbine, HBI-rotary thermal power plants with high technical and economic indicators. Kazakhstan group of scientists-enthusiasts on the use of wind energy in order to reduce the level of incoming greenhouse effects over the past 20 years has been developing vertical-axial devices (Darrieus type) with two coaxially arranged rotation rolls.
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    RESISTANCE OF HEAT-RESISTANT YTTRIUM-CONTAINING SEALING COATINGS TO MECHANICAL FRACTURE WHEN FORMING CUTTING PATHS
    (2024-09-30)
    Вадим Іванович Кубіч
    ;
    Ye. Fasol
    ;
    O. Cherneta
    ;
    A.K. Yershina
    ;
    N.Z. Sakipov
    According to the results of tribotechnical tests of coatings made of KNA-82 alloy ligatures with the addition of yttrium of 0.1%, 0.3%, 0.5%, data were obtained that allowed us to establish the nature of changes in the dynamic coefficient of friction over the test period and numerous values of the energy intensity of material wear. The evaluation of coatings formed by the gas-flame and ion-plasma method was based on the following premise. The maximum resistance to mechanical fracture is determined by the manifestation of a constant minimum value of the dynamic coefficient of friction. This serves as an indicator of reduced friction force before reaching the fatigue limit. Another key factor is the number of separated particles produced per unit of integral work during the friction process. These evaluation parameters are lined up in a row by the number of points from 1 to 4. The maximum score corresponds to the maximum resistance, i.e., a lower value of the energy intensity of material wear and the minimum value of the stable friction coefficient. It has been determined that the same coincidence of these parameters according to the scores is almost at all stages of testing (I-III) was the coating formed by the gas-flame method with a yttrium concentration of 0.3%-0.5%. The exception was the coating formed by the ion-plasma method with a yttrium concentration of 0.1% at the fourth stage of testing.
    Цитирования (OpenAlex) 3Цитирования (OpenCitations) 3
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    Experimental and Computational Study of the Aerodynamic Characteristics of a Darrieus Rotor with Asymmetrical Blades to Increase Turbine Efficiency Under Low Wind Velocity Conditions
    (Multidisciplinary Digital Publishing Institute, 2025-04-03)
    Muhtar Isataev
    ;
    Rustem Manatbayev
    ;
    Zhanibek Seydulla
    ;
    Nurdaulet Kalassov
    ;
    A.K. Yershina
    In this study, we conducted experimental and numerical investigations of a Darrieus rotor with asymmetrical blades, which has two structural configurations—with and without horizontal parallel plates. Experimental tests were conducted in a wind tunnel at various air flow velocities (ranging from 3 m/s to 15 m/s), measuring rotor rotation frequency, torque, and thrust force. The computational simulation used the ANSYS 2022 R2 Fluent software package, where CFD simulations of air flow around both rotor configurations were performed. The calculations employed the Realizable k-ε turbulence model, while an unstructured mesh with local refinement in the blade–flow interaction zones was used for grid generation. The study results showed that the rotor with horizontal parallel plates exhibits higher aerodynamic efficiency at low wind velocities compared to the no-plates rotor. The experimental findings indicated that at wind speeds of 3–6 m/s, the rotor with plates demonstrates 18–22% higher torque, which facilitates the self-start process and stabilizes turbine operation. The numerical simulations confirmed that horizontal plates contribute to stabilizing the air flow by reducing the intensity of vortex structures behind the blades, thereby decreasing aerodynamic drag and minimizing energy losses. It was also found that the presence of plates creates a directed flow effect, increasing the lift force on the blades and improving the power coefficient (Cp). In the case of the rotor without plates, the CFD simulations identified significant low-pressure zones and high turbulence regions behind the blades, leading to increased aerodynamic losses and reduced efficiency. Thus, the experimental and numerical modeling results confirm that the Darrieus rotor with horizontal parallel plates is a more efficient solution for operation under low and variable wind conditions. The optimized design with plates ensures more stable flow, reduces energy losses, and increases the turbine’s power coefficient. These findings may be useful for designing small-scale wind energy systems intended for areas with low wind speeds.
    Цитирования (OpenAlex) 6Цитирования (OpenCitations) 5
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    Integrated Approach to Aerodynamic Optimization of Darrieus Wind Turbine Based on the Taguchi Method and Computational Fluid Dynamics (CFD)
    (Multidisciplinary Digital Publishing Institute, 2025-05-20)
    Nurdaulet Kalassov
    ;
    Zhandos Baizhuma
    ;
    Rustem Manatbayev
    ;
    A.K. Yershina
    ;
    Muhtar Isataev
    This paper presents a numerical study of the optimization of the geometric parameters of a four-bladed Darrieus vertical-axis wind turbine (VAWT) with a NACA 0021 aerodynamic profile. The aim of the study was to increase the aerodynamic efficiency of the turbine by selecting optimal values of the rotor diameter and blade chord length. The Taguchi method using an orthogonal array was used as an optimization method, which reduced the number of necessary calculations from 77 to 20 while maintaining the reliability of the analysis. CFD modelling was performed in the ANSYS 2022 R2 Fluent software environment based on a two-dimensional non-stationary model, including a full rotor revolution and an analysis of the steady-state mode for the twentieth cycle. As a result of the analysis, the optimal parameters were determined: rotor diameter D = 3 m and chord length c = 0.4 m. Additionally, for the selected configuration, the numerical model was validated by constructing the dependence of the power coefficient Cp on the tip speed ratio λ in the range from 0.2 to 2.8. The maximum value of Cp was 0.35 at λ = 2.2, which is an increase of ~64% compared to the least efficient rotation mode in the considered range of λ. The obtained results allow us to conclude that the Taguchi method can be used in combination with CFD modelling for fast and accurate optimization of the aerodynamic parameters of low-power wind turbines.
    Цитирования (OpenAlex) 9Цитирования (OpenCitations) 9