Faculty of Mechanical Engineering

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Determination of the thermo-physical properties of municipal solid waste from the perspective of its energy utilization
(2025-04)
Uler-Zefikj, M., Filkoski, R., & Shesho, I.
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Characterization and Comparative Assessment of Exhaust Gas Emissions from Municipal Solid Waste Incineration
(2025-09)
Uler-Zefikj, M., & Filkoski, R.
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Multi-Criteria Decision-Making Approaches for Evaluating Waste-to-Energy Scenarios
(2025-05)
Argilovski, A., Uler-Zefikj, M., & Filkoski, R.
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Risk Mitigation Strategy for the Installation of a WtE Cogeneration Plant in the City of Skopje
(2025-05)
Uler-Zefikj, M., Argilovski, A. & Filkoski, R.
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Local biomass potential for syngas production and further conversion into synthetic fuel
(2024-04)
Uler Zefikj, M., Filkoski, R., & Tashevski, D.
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Evaluation of the energy potential of biomass and textile waste for replacing fossil fuels in the cement industry
(2023-09)
Uler Zefikj, M., Filkoski, R., & Dimitrovski, D.
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Optimized blade design through numerical analysis for enhanced wind turbine performance
(Faculty of Mechanical Engineering and Naval Architecture, Zagreb, 2025-10-10)
Lazarevikj, M.
;
Zefikj Uler, M.
;
Zdravkovska, I.
;
Vasileska, E.
;
Iliev, V.
In recent years, the urgency for transitioning to renewable energy sources (RES) has intensified, as approximately 75% of global greenhouse gas emissions result from fossil fuel use. Among RES, wind energy stands out for its low cost, environmental benefits and ongoing technological improvements. Although recent studies have identified several locations in the Republic of North Macedonia (RNM) with high wind energy potential, the country's wind resources remain largely underutilized, and research on turbine design optimized to local conditions is lacking. Given the fluctuating nature of wind energy, increasing the efficiency and reliability of wind power systems has become a key focus of the wind turbine industry through innovative approaches in their design and implementation. In response to this gap, the present study investigates blade design optimization for a specific high-potential location in RNM, addressing the absence of studies that adapt aerodynamic design to the country’s wind conditions. The study aims to improve the performance of a horizontal axis wind turbine (HAWT), by applying an optimization methodology based on mathematical modelling and simulation techniques. The study is conducted for a predetermined wind speed range, which is chosen according to the conditions at the specific location. For a desired installed power and the basic geometric and operating parameters of a HAWT, several suitable aerodynamic blade profiles were investigated. After an evaluation of the airfoils, a selection was conducted on the basis of their aerodynamic performance. The selected airfoil was used for the HAWT rotor blades composition. Three models of rotor blades were developed based on different chord length and twist angle distributions. A numerical model was developed using a software tool to simulate the flow through the blades with different geometries to predict their impact on the HAWT performance at various operating conditions. These simulations yielded the output parameters that characterize the wind turbine performance. The simulation results provided valuable insights into how blade geometry affects overall turbine behaviour and efficiency. The outcomes confirm that the proposed optimization methodology can support the selection of site-specific blade designs, improving wind turbine performance and revealing new opportunities for efficient and localized wind energy production in RNM.
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PHYSICS-BASED DATA-DRIVEN METHODS FOR DIAGNOSTICS OF ROTATING MACHINERY
(Faculty of Technical Sciences Trg Dositeja Obradovića 6, Novi Sad, Republic of Serbia, 2022-12)
Ignjatovska Anastasija
;
Velkovski Trajce
;
Petreski Zlatko
;
Anachkova Maja
Maintenance of rotating machinery is the essential part and core of every production process which directly affects its productivity and quality. As the level of complexity of modern rotating machinery grows, the need for an effective and efficient maintenance process increases as well. Based on numerous scientific papers in the field of condition monitoring, a conclusion can be drawn that the best indicator of the overall current state of the machine, which is sensitive to the appearance and development of a certain defect at the earliest stages is vibration. In order to accurately monitor and determine the current state of the machinery by measuring its vibrations, automation of the process of monitoring the condition and identification of possible faults has to be performed. The methods for automation generally can be divided into two large groups, physics-based and data-driven methods. This research gives an insight into the state-of-the-art of both methods and enhances their advantages and limitations. In order to overcome these limitations and take advantage of both, in the past few years a novel methodology in the field of rotating machinery diagnostics is proposed, the physics-based data-driven method. This research concentrates on discovering the potential for future work on physics-based data-driven methods in the field of rotating machinery. The first goal of this research would be the integration of purely physics-based models and purely data-driven models into a single hybrid model that would serve for vibration-diagnostic monitoring of the condition of rotating machines. In addition, the obtained from the hybrid model would be compared to the results obtained from the purely data-driven models, based on the obtained accuracy, the volume of the database, and calculation costs and time. In this way, it would be possible to conclude which method is superior for vibration-diagnostic monitoring of the condition of rotating machines.
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AGING MANAGEMENT APPROACHES FOR HYDROGEN PRODUCTION PLANTS
(Faculty of Technical Sciences Trg Dositeja Obradovića 6, Novi Sad, Republic of Serbia, 2022-12)
Grncharevska Elena
;
Chaloska Jasmina
;
Velkovski Trajce
Aging is the effect whereby a component suffers some form of material deterioration and damage (The Health and Safety Executive - HSE). Most affected places at hydrogen production plants that suffer from corrosion, hydrogen embrittlement, thermal fatigue and other damage mechanisms are piping and fixed equipment (electrolysers and storage tanks). High operating temperatures and unexpected shutdowns have significant contribution at accelerating the ageing process. Successful aging management is critical to the safety performance, but it is also affected by staff demographics, skills, training, and competencies. Due to the nature of the process, some plants are more susceptible to the aging effect than others. Current approach to asset management is reactive and the focus is on carrying out work that must be done now, rather than work that will prevent future problems. The result is often unanticipated failures, long backlogs of maintenance work and no time to carry out the preventive maintenance which would alleviate many of the problems. A proactive approach with thorough understanding of asset aging mechanisms and conditions and the ways in which assets interact is crucial for effectively managing the aging and ensure that the assets operate efficiently and safely. This research is focused on providing an overview of three aging management methodologies for hydrogen production plants which operate under critical conditions and are subject to rapid deterioration: Regulatory-based aging management; Risk-based aging management according to API 570, 580, 563, 574; and Economic-based ageing management. The legal framework is insufficient to control the aging process and related risks, therefore criticality screening and risk-based inspections are the key to prevent unexpected catastrophic failures, unscheduled downtime, and business interruption. Defining the business-critical equipment and stock of spare parts finalize the aging management process from economic point by reducing the downtime.
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REMOO–2015: “Overview of the 5th International Conference & Workshop, Technological, Modelling and Experimental Achievements in Energy Generation Systems”
(2016)
Lazarevska A. M.

Faculty of Mechanical Engineering

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