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Challenges in the design of a new centrifugal fan with variable impeller geometry

Odyjas Piotr, Więckowski Jędrzej, Pietrusiak Damian, Moczko Przemyslaw

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 1

16--27

EN

This article presents a description of design work for newly created centrifugal fans. This was done based on the example of an innovative solution that uses a change in impeller geometry. In the described solution, this is achieved by shortening and lengthening the impeller blades. The development of a technical solution with such properties requires a change of approach in the design process compared with classic solutions. Therefore, the following text describes this process from the concept stage to demonstrator tests. The principle of operation of such a solution is presented and the assumptions made based on analytical calculations are also described. The text also shows a 3D model of the centrifugal fan with variable impeller geometry, made with the help of computer aided design (CAD) tools. In the further part, numerical calculations were made on its basis. The finite element method (FEM) calculation made it possible to verify the structural strength of the project and its modal properties as well as to verify flow parameters, thanks to the use of computational fluid dynamics (CFD) calculations. The next step describes the procedure for testing centrifugal fans with variable rotor geometry, which is different from that of fans without this feature. The next part presents the results of research from the tests carried out.

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The use of thermoelastic stress analysis for stress distribution evaluation of an industrial equipment under regular operating conditions

Misiewicz Robert, Moczko Przemyslaw, Boyce Bradley

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e106

EN

Thermoelastic stress analysis (TSA) is an experimental technique enabling the determination of stress pattern and level. Because of the dependence of the technique on a temporally changing load on the target structure, it is mainly considered as a technique suited to the laboratory, and therefore there is a dearth of real-world industrial applications. An experimental study of TSA applicability in determining the stress level distribution in a heavy industrial equipment joint (a bucket wheel excavator joint) under ordinary operating conditions was conducted. In the research, TSA and strain gauge measurements were validated with numerical computations. As the first step of validation, a numerical finite element analysis (FEA) was implemented. The authors then introduced an innovative approach to calibrating TSA results, which implements Rainflow decomposition of strain gauge measurements. Furthermore, a numerical validation approach based on modal frequency response analysis was implemented. Both the experimental and numerical approaches gave remarkably similar results, thereby confirming the possibility of effective use of thermoelastic stress analysis in industrial applications outside the laboratory.

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Adaptation of the machine to the new geological conditions – excavation unit redesign and optimization

Andruszko Jakub, Moczko Przemyslaw, Pietrusiak Damian

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 3

art. no. e137122

EN

The paper presents and sums up the research and technical aspects of the modernization of the cutting tool of the dredger. Improper adjustment of the cutting elements not adjusted to the characteristics of excavated material is not an uncommon situation, causing versatile geological conditions. Relocation of the machines from one pit to another may result in the significant influence on the excavation process (wear, output, etc.). Common practice is the field try and error approach to obtain desired machine performance. In the paper authors present the approach with aid of cutting-edge technologies. Coupled DEM and kinematic simulations supported by the reverse engineering technologies of laser scanning were the fundamental drivers for final adjustments of the cutting tool at its present operational conditions.