Vibrations in engineering and technology

Elchyn Aliiev – Doctor of Technical Sciences, Senior Researcher, Professor of the Departments of Mechanization of Production Processes in Animal Husbandry of Dnipro State Agrarian and Economic University (St. S. Efremova, 25, Dnipro, Ukraine, 49000, e-mail: aliev@meta.ua, https://orcid.org/0000-0003-4006-8803).

Ruslan Ponomarenko – postgraduate of Dnipro State Agrarian and Economic University (St. S. Efremova, 25, Dnipro, Ukraine, 49000, e-mail: Ponomarenko240314@gmail.com, https://orcid.org/0009-0002-0282-8285).

A comprehensive numerical simulation of the mixing process of feed premixes in a Y-shaped mixer was carried out using the Discrete Element Method (DEM) combined with Computational Fluid Dynamics (CFD–DEM) in the Simcenter Star-CCM+ software environment. The aim of the study was to establish the patterns of influence of the mixer’s geometric parameters (branch convergence angle, branch diameter, and branch length) and operating factors (mixer rotation speed) on the rate of achieving the target mixture uniformity, the flow behavior of particles, and energy consumption.

The simulation was performed in a three-dimensional setting, where solid premix particles were modeled as spherical bodies, taking into account elasticity, friction, and restitution during particle-to-particle and particle-to-wall contacts using the Hertz–Mindlin model. Visualization of the process made it possible to trace the formation of multi-stream trajectories, local accelerations and decelerations of particles, as well as the dynamics of the gradual leveling of premix component concentrations.

The study was conducted according to a full-factorial experimental design with four factors at three levels, with the process efficiency criterion defined as the mixing time τ required to achieve mixture uniformity h = 0.95. Based on the simulation results, a second-order regression equation was obtained, and statistical evaluation of factor significance was carried out using Student’s t-test and Fisher’s F-test. The analysis showed that the mixer rotation speed and branch convergence angle have the greatest influence on the rate of achieving uniformity, which is explained by active flow circulation, turbulence, and effective intermixing of premix components. Branch diameter and length exhibited a smaller nonlinear effect: excessive increases in these parameters can create “dead zones” and reduce mixing intensity. Cross-factor interactions confirmed the complex nature of the influence of geometry and operating conditions on process efficiency.

Through compromise optimization aimed at minimizing the mixing time while simultaneously increasing mixer capacity, the following rational parameters of the Y-shaped mixer were determined: branch length L = 371 mm, diameter D = 186 mm, convergence angle γ = 46°, and rotation speed n = 22 rpm. Under these conditions, the mixing time to reach uniformity was 69 seconds.

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13. Shevchenko I. Aliiev E. (2020). Improving theefficiency ofthe process ofcontinuous flowmixing of bulkcomponents. Eastern-European Journal of Enterprise Technologies, 6/1 (108), 6–13. DOI: https://doi.org/10.15587/1729-4061.2020.216409

14. Aliiev E., Pavlenko S., Aliieva O., Morhun O. (2021). Accelerated biothermal composting of manure-compost mixture. Agraarteadus, Journal of Agricultural Science, XXXII (2), 169–181. DOI: https://doi.org/10.15159/jas.21.30

15. Aliiev E. B., Koshulko V. S., Kocherezhko N. V. Obgruntuvannya konstruktyvno-tekhnolohichnykh parametriv rotornoho zmishuvacha kombikormiv periodychnoyi diyi [Substantiation of the design and technological parameters of a rotary mixer of compound feeds of periodic action]. Tekhnika, enerhetyka, transport APK, 2023, 3 (122), 5–13. DOI: https://doi.org/10.37128/2520-6168-2023-3-1. [in Ukrainian].

16. Aliiev E. B., Pavlenko S. I. Symulyatsiya protsesu formuvannya burta i zmishuvannya komponentiv kompostnoyi sumishi odnobarabannym aeratorom [Simulation of the process of forming a ridge and mixing the components of the compost mixture with a single-drum aerator]. Vibratsiyi v tekhnitsi ta tekhnolohiyakh, 2023, 2 (109): 30-39. DOI: https://doi.org/10.37128/2306-8744-2023-2-4. [in Ukrainian].

17. Aliiev E. B. Chyselʹne modelyuvannya protsesiv ahropromyslovoho vyrobnytstva: pidruchnyk [Numerical modeling of agroindustrial production processes: textbook]. Kyyiv: Ahrarna nauka, 2023, 340 s. DOI: https://doi.org/10.31073/978-966-540-584-9. [in Ukrainian].

18. Aliiev E. B., Mykolenko S. YU., Sova N. A. ta in. Tekhniko-tekhnolohichne zabezpechennya bezvidkhodnoyi pererobky zernovoyi syrovyny u kharchovi produkty i kormy: kolektyvna monohrafiya [echnical and technological support for waste-free processing of grain raw materials into food products and feed: collective monograph] / za zah. red. E. B. Aliyeva. Dnipro: LIRA. 2022, 192 s. [in Ukrainian].