Yazar "Mollahasanoglu, Hakki" seçeneğine göre listele

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    Design and initial experimental verification of a high-speed electrodynamic levitation measurement system utilizing modular magnetic field sources and aluminium rails
    (Elsevier Sci Ltd, 2025) Ozturk, U. Kemal; Mollahasanoglu, Hakki; Abdioglu, Murat; Okumus, Halil Ibrahim; Gedikli, Hasan
    This work presents design and development of a modular high-speed electrodynamic levitation (EDL) test system that integrates advanced magnetic field configurations and real-time control capabilities at high operational speeds. The system comprises a rotating aluminium rail and interchangeable magnetic field sources, including permanent magnet array (PMA) and high-temperature superconducting (HTS) bulk, allowing for a variety of experimental configurations. The initial experimental results focused on testing the system through PMA-aluminium rail and HTS-aluminium rail configurations. A key innovation of this system is its modular structure, which allows for easy replacement and reconfiguration of magnetic components and rail geometries. The adaptability of the system enables a thorough investigation of how different magnetic field sources influence magnetic force and dynamic stability at high speeds. Furthermore, the system is fully integrated with a programmable logic controller (PLC) and supervisory control and data acquisition (SCADA) interface, enabling precise real-time monitoring, synchronized control and automatic data acquisition. Experimental results demonstrate the system's capability to measure vertical displacement variations and force fluctuations at different speeds, with resonance effects identified around 145 km/h. The levitation forces of 99 N were measured at a gap of 10 mm, with the PMA at a maximum speed of 283 km/h above an aluminium rail, while it was measured as 16 N with HTS at a vertical gap of 9 mm. This flexible test platform provides a critical foundation for determining the force parameters of the real-scale EDL Maglev technologies and advancing their practical application potential in high-speed transportation.
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    Enhancing magnetic levitation and guidance force and weight efficiency of high-temperature superconducting maglev systems by using sliced bulk YBCO
    (Wiley, 2023) Abdioglu, Murat; Ozturk, U. Kemal; Guner, Sait Baris; Ozturk, Mehmet; Mollahasanoglu, Hakki; Yanmaz, Ekrem
    We aimed to enhance the magnetic force efficiency of Maglev systems without increasing total weight. For this aim, we divided YBCO bulks into three slices horizontally to utilize the YBCO-permanent magnetic guideway (PMG) interaction surface as much as possible. We used whole YBCO above PMGs with different magnetic pole directions (PMG-A and PMG-B) in two lying positions of transversal and longitudinal and investigated levitation and guidance force performances. It is determined that levitation and guidance forces by using YBCO in transversal lying mode are bigger compared to the longitudinal mode. For sliced YBCO, the maximum levitation force increased by 69% and 78%, while the guidance force enhancements are determined as 212% and 91%, compared to the whole YBCO above PMG-A and PMG-B, respectively. The levitation and guidance force density with respect to the total mass of unit a set of slices YBCO increased by 92% and 106%, respectively, compared to the whole YBCO above PMG-B in transversal mode. Since the higher levitation force and the lower total weight of the onboard unit are important parameters in point of the energy efficiency in Maglev and other levitation applications, the result of this study supplies useful data for the engineers and industrial partners.
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    Experimental investigation of magnetic forces in PMA and HTS configurations using a high-speed electrodynamic levitation test system
    (Elsevier Sci Ltd, 2026) Mollahasanoglu, Hakki; Abdioglu, Murat; Ozturk, Ufuk Kemal; Okumus, Halil Ibrahim
    This study presents a comparative experimental investigation of magnetic force parameters in high-speed electrodynamic levitation systems using permanent magnet arrays and high-temperature superconductors. A novel modular test platform with a rotating aluminium rail, cryostat, and integrated three-axis force measurement unit was employed to evaluate levitation and drag forces under controlled conditions at linear velocities up to 280 km/h. Three different permanent magnet arrays configurations were designed and tested at working gaps of 10, 12, and 15 mm, while high-temperature superconductors bulks fabricated from YBCO by the top-seed-meltgrowth method were tested at 10 and 12 mm gaps. The experimental results demonstrated that permanent magnet arrays configurations produced higher levitation forces, with a maximum of 100 N at working gap of 10 mm. High-temperature superconductors bulks, in contrast, generated lower levitation forces (maximum 17 N at 10 mm) due to limited trapped flux (similar to 0.25 T) but showed the advantage of substantially reduced drag forces (3.5 N at 10 mm). A lift-to-drag ratio analysis confirmed the trade-off between force generation and energy losses in permanent magnet arrays systems, while highlighting the efficiency potential of high-temperature superconductors-based levitation. The findings of this study provide valuable insights for the engineering development of high-temperature superconductors-based Maglev technologies, emphasizing their potential importance in future transportation systems.
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    Extended 2-D Magnetic Field Modeling of Linear Motor to Investigate the Magnetic Force Parameters of High-Speed Superconducting Maglev
    (IEEE-Inst Electrical Electronics Engineers Inc, 2023) Ozturk, Ufuk Kemal; Abdioglu, Murat; Ozkat, Erkan Caner; Mollahasanoglu, Hakki
    A 2-D numerical finite-element model of a linear synchronous motor (LSM) is extended based on the magnetic field and moving mesh properties to investigate the magnetic flux and magnetic force characteristics of the high-speed electromagnetic levitation Maglev system, by using high-temperature superconductor (HTS) coils rather than lower current-carrying copper coils on the onboard unit and permanent magnets (PMs) on the ground. In this 2-D LSM model, the transient time-dependent solver is used to obtain the magnetic flux densities. Both the propulsion and levitation forces increased with increasing supercurrent J(c0) values indicating the advantage of using the superconducting windings in PM-LSM of Maglev vehicles as compared with the copper wires. It was also determined that, although the propulsion force is obtained on a comparable level with the studies in the literature, the lower levitation force issue than the electrodynamic suspension (EDS), despite the better propulsion to levitation force ratio, can be overcome by using the high flux trapping capacity bulk HTSs on the onboard unit together with the superconducting coils. The determined higher propulsion force in this PM-LSM Maglev model indicates that the Maglev vehicle can reach higher velocities in a short distance, and thus, this vehicle can be effectively used in short-distance travels in addition to the long-distance transportation. On the other hand, since the EDS system to be accelerated in a certain time interval via conventional wheels to achieve sufficient levitation, PM-LSM system can be integrated into the EDS Maglev system to ensure higher acceleration in a short time interval in addition to the higher levitation and propulsion force performances.
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    Magnetic Force Performance of Hybrid Multisurface HTS Maglev System With Auxiliary Onboard PMs
    (IEEE-Inst Electrical Electronics Engineers Inc, 2023) Ozturk, U. Kemal; Abdioglu, Murat; Mollahasanoglu, Hakki
    The vertical levitation force, guidance force, and magnetic stiffness values, and thus the loading capacity and movement stability of high-temperature superconducting (HTS) Maglev systems, are aimed to be increased in this study by using auxiliary permanent magnets (PMs) in the onboard unit together with the multisurface HTS-permanent magnetic guideway (PMG) arrangement (hybrid multisurface arrangement). First, the magnetic levitation force, guidance force, and stiffness performances of the hybrid multisurface arrangement were investigated at different field cooling heights (FCH). Then, to compensate for the negation of instability that results from the higher repulsive force between the onboard PMs and the PMG and to obtain an optimal magnetic field medium, we have changed the vertical position of the auxiliary onboard PMs (Z(PM)) to Z(PM) = 0, 2, and 4 mm, at the cost of a bit of adecrement in the vertical levitation force. The bigger levitation force, together with the guidance force values for FCH = 25 mm and Z(PM) = 0 mm, indicates that the hybrid multisurface HTS-PMG arrangements are beneficial to increasing the practical applicability of Maglev systems.
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    Numerical Investigation of EDS Maglev Systems in Terms of Performance and Cost for Different PMs-Aluminum Rail Arrangements
    (Springer, 2025) Mollahasanoglu, Hakki; Abdioglu, Murat; Ozturk, Ufuk Kemal; Okumus, Halil Ibrahim; Coskun, Elvan; Gencer, Ali
    Permanent-magnet electro-dynamic suspension (PMs-EDS) maglev systems are shaping the future of modern transport by providing high-speed, energy-efficient, and sustainable transport solutions. In this study, numerical simulations were performed to determine the optimum geometrical parameters of aluminum rail and permanent magnet arrangements for EDS systems. For that, the aluminum rail and permanent magnet combinations were investigated, and then the same simulations were repeated by creating cavities in the aluminum rails for cost efficiency. The highest levitation-to-drag ratio (LDR) was achieved with magnet arrays having a fill factor of 0.4, 20 mm thick aluminum, and an aluminum rail width of 60 mm. Additionally, by creating cavities into the rails, it was calculated that approximately $2.44 million could be saved from the total cost of $17.34 million cost of the 1000 km double-strip aluminum rails, with negligible reduction in the LDR ratio. The findings of this study provide a sustainable and economical transport solution by increasing the cost effectiveness of PMs-EDS maglev systems. The results obtained may pave the way for the development of different types of applications of maglev technology and increase the potential for commercial use of maglev transport systems.