Yazar "Mollahasanoglu, Hakki" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    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.
  • 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
    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.