Yazar "Ozturk, Ufuk Kemal" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    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.
  • Küçük Resim Yok
    Öğe
    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.
  • Küçük Resim Yok
    Öğe
    Investigation of interior seed effects on levitation force in Melt-Grown YBCO superconductors by experimental and numerical methods
    (Elsevier Sci Ltd, 2025) Ozturk, Ufuk Kemal; Abderrahmane, Babe Cheikh; Uzun, Oguzhan; Abdioglu, Murat; Guner, Sait Baris; Queval, Loic
    This study introduces a novel Top-Interior Multi-Seeding Melt Growth (TI-MSMG) technique for fabricating highperformance YBCO bulk superconductors and explanations some physical background based on FEM modelling. The depth of the interior seed was gradually changed as 0, 2 and 4 mm (samples S0, S2 and S4, respectively) from the upper surface of the samples. By incorporating an interior seed into the precursor pellet, the TI-MSMG method enables systematic control over grain morphology and critical current density distribution. Magnetic levitation and guidance forces were measured using a three-axis force measurement system, and a twodimensional finite element method (FEM) model based on the H-formulation of Maxwell's equations was developed to simulate the electromagnetic behaviour of the superconductors with different seed positions. Experimental and modelling results reveal that samples incorporating an interior seed (S2) exhibit significantly enhanced levitation and guidance forces compared to S0 and S4, attributable to improved inter-domain interactions and morphological consistency, so a better current coupling. The numerical simulations accurately reproduced the experimental findings, confirming the validity of the modelling approach. These findings indicate that the TI-MSMG process not only addresses some limitations of conventional top-seeding methods but also enhances levitation force performance through optimization of interior seed depth, thereby enabling more efficient and tailored designs for high-temperature superconducting systems such as magnetic levitation, energy storage, and superconducting motors.
  • Küçük Resim Yok
    Öğe
    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.