İlgi alanları

• MakaleYayıncıda açık erişim2026/r/bayburt/12770
  Finite element analysis driven optimization of an electrodynamic levitation system with permanent magnet Halbach arrays

  Ozkat, Erkan Caner; Abdioglu, Murat; Ozturk, U. Kemal

  This study presents a finite element analysis (FEA)-driven optimization for the design of an electrodynamic levitation (EDL) system incorporating permanent magnet Halbach arrays (PM-HAs). The primary objective is to maximize the net force difference between lift (Fy) and drag (Fx) forces under realistic physical and manufacturing constraints. The nonlinear electromagnetic behavior of the EDL system is modeled using high-fidelity FEA, capturing the complex interaction between the PM-HA and a conductive plate. At each iteration of the population-based optimization algorithm, full magnetoquasistatic simulations are performed to ensure a physically accurate evaluation of key performance metrics. A comprehensive parametric study involving 256 distinct PM-HA configurations reveals a non-monotonic relationship between the number of magnets and levitation performance, highlighting the critical role of magnetic field distribution. Configurations with 9 to 11 magnets achieve the highest net levitation force. The optimization results indicate that the optimal configuration includes four horizontally aligned permanent magnets (PMs) with a width of 74.00 mm and three vertically aligned PMs with a width of 74.67 mm, along with a 7 mm thick conductive plate having a conductivity of 5 ×107 S/m. This design delivers a maximum lift force of 3550 N and a minimum drag force of 279 N at 100 m/s. The findings demonstrate that effective EDL system design requires a carefully arranged magnet configuration rather than a simple maximization of magnet count or size. The proposed FEA-guided framework offers a robust and scalable methodology for the optimization of high-performance Maglev systems.

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• MakaleYalnız künye2026/r/bayburt/12757
  Investigation of magnetic levitation performance in Ag-added DyBa2Cu3O7-δ superconductors fabricated by single-direction melt growth (SDMG) method

  Doğruer, M.; Abdioğlu, M.; Motoki, T.; Ozturk, U. Kemal

  Abstract This study investigates the magnetic levitation and guidance characteristics of Ag-doped DyBa2Cu3O7-δ superconducting bulks, synthesized by the single-direction melt growth (SDMG) technique. The levitation force, vertical stiffness and lateral guidance force are measured at varying cooling heights (CHs) of 5 mm, 25 mm and 50 mm, with a constant working height (WH) of 5 mm for lateral force measurements. DyBa2Cu3O7-δ samples are cooled using liquid nitrogen (77 K) and thermal stabilization is achieved before force data collection. Results show that levitation forces increase with CH, while the levitation force curves exhibit both attractive and repulsive behavior depending on the CH. The lateral guidance force is higher for the Ag2 sample than for the Ag1 sample and decreased as the temperature decreased. Vertical stiffness also increased with CH and decreased as the levitation gap decreased, confirming heightened guidance forces at smaller distances. The flux density distributions, including both lateral ( B x ) and vertical ( B y ) components, are found to significantly impact the levitation and guidance force performance. Specifically, configurations with concentrated B x gradients improved levitation stability, while configurations with distributed B y led to stronger guidance forces. These findings underscore the importance of optimizing the PMG design to balance B x for levitation and B y for guidance in superconducting systems.

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• MakaleYalnız künye2026/r/bayburt/11180
  Investigation of the levitation and drag force parameters of the electrodynamic maglev based on Halbach array of HTS bulks on aluminium rail

  Ozturk, U.Kemal; Yıldız, Ali Suat; Abdioglu, Murat

  This study aims to investigate the performance parameters of high-temperature superconducting (HTS) bulks and permanent magnets (PMs) as magnetic field sources in electrodynamic suspension (EDS) systems, with the goal of enhancing the currently low magnetic lift force and reducing the high drag force in such systems. A numerical analysis is conducted on an EDS system utilizing Halbach arrays of HTS and PM bulks. The H-formulation within the Partial Differential Equation (PDE) module is employed to simulate the flux-trapping performance of the HTS bulks, with results verified by experimental data from the literature. The lift and drag forces between the arrays and an aluminium rail are investigated using the Rotating Machinery-Magnetic module of COMSOL. It is observed that increasing the width of the central sample in the array results in a higher peak value of the vertical magnetic flux density and a broader peak profile, indicating a more extended effective magnetic field region across the rail surface. The HTS-based system exhibits significantly higher lift force and loading capacity compared to its PM-based counterpart. Specifically, a Halbach array composed of three HTS bulks (10 mm, 70 mm, 10 mm widths; HTS#10-70-10) achieves a better lift force representing a 211.5 % increase over the PM array. Furthermore, the lift-to-drag ratio (LDR) of the HTS array improves by 17.2 %. The results indicate that the HTS arrays offer superior performance in terms of both lift force and energy efficiency, highlighting their potential for enhancing the applicability of HTS-EDS systems in real-scale applications. This study features the advantages of HTS-based systems in achieving higher loading capacities and more efficient operation conditions compared to the PM arrays.

  AtıfScopus1·WoS1

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• MakaleYalnız künye2026/r/bayburt/11152
  Experimental investigation of magnetic forces in PMA and HTS configurations using a high-speed electrodynamic levitation test system

  Mollahasanoglu, Hakkı; 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-melt-growth 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 (∼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.

  AtıfScopus5·WoS4

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• MakaleYalnız künye2025/r/bayburt/12814
  Investigation of interior seed effects on levitation force in Melt-Grown YBCO superconductors by experimental and numerical methods

  Öztürk, Ufuk Kemal; Abderrahmane, Babe Cheikh; Uzun, Oğuzhan; Abdioğlu, Murat; Güner, Sait Barış; Quéval, Loïc

  This study introduces a novel Top-Interior Multi-Seeding Melt Growth (TI-MSMG) technique for fabricating high-performance 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 two-dimensional 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.

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• MakaleYalnız künye2025/r/bayburt/12653
  Experimental and numerical investigation of flux trapping in bulk YBCO under different permanent magnet configurations

  Uzun, Oguzhan; Abdioglu, Murat; Ozturk, U. Kemal

  This study investigates flux trapping in bulk YBaCuOx (YBCO) high-temperature superconductors (HTS) under various permanent magnet configurations (PMCs) through both experimental and numerical methods. A finite element method (FEM) based on the H-formulation of Maxwell's equations is employed to simulate the HTS-PM interaction, showing good agreement with experimental results in peak trapped flux density values. The maximum trapped flux densities for PMC-1, PMC-2, PMC-3, and PMC-4 were measured as 207 mT, 359 mT, 392 mT, and 478 mT, respectively, demonstrating the significance of PMC design in optimising flux trapping in HTS materials. Enhanced flux trapping was observed with configurations including additional permanent magnets, such as PMC-2 and PMC-4, yielding trapped flux efficiencies of 77.5 % and 55.0 %, respectively. Obtained results in trapped flux efficiency are very impressive as compared to a value of 23 % trapped flux efficiency in literature in which a solenoid magnet with a 3 T peak value of magnetic flux density is used to trap a magnetic field in the HTS. The magnetic flux trapping methodology of this research is very effective for magnetic bearing applications with self-stabilisation in which high magnetic fields are not needed since it doesn't need any magnetic field sources with complex structures, such as coils, to facilitate the magnetic field trapping in the HTSs.

  AtıfScopus3·WoS3

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• MakaleYalnız künye2025/r/bayburt/11403
  Design and initial experimental verification of a high-speed electrodynamic levitation measurement system utilizing modular magnetic field sources and aluminium rails

  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.

  AtıfScopus3·WoS3

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• MakaleYalnız künye2025/r/bayburt/11284
  Numerical Investigation of EDS Maglev Systems in Terms of Performance and Cost for Different PMs-Aluminum Rail Arrangements

  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.

  AtıfScopus4·WoS5

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• MakaleYalnız künye2024/r/bayburt/13144
  AC transport loss analysis of HTS stack busbars for all-electric aircraft with harmonics and DC offset considerations

  Abdioglu, Murat; Gautam, Gaurav; Zhang, Min; Yuan, Weijia

  This paper presents a study of the current carrying capacity and AC loss of high-temperature superconducting (HTS) stacks to be used in busbar applications for all-electric aircraft. A 2D model was developed using COMSOL Multiphysics with a T-A formulation for detailed analysis. The study began by applying a stable 20 kA DC offset current to the HTS stacks to simulate practical operating conditions. Firstly, the behaviour of the critical current was studied under self-field conditions for stacks with different numbers of HTS tapes and spacing. Secondly, AC ripple currents were introduced with DC offsets, and the effects of 3rd and 5th harmonic distortions (HD) were studied. The results show that configurations with 40 tapes and gaps of more than 2 mm are considered suitable for safe current transport under DC conditions. On the other hand, increasing the tape spacing leads to an increase in the safe transport current ripple due to the reduced magnetic field interaction within the stack. In addition, the transport loss decreases as the air gap increases due to the reduction in the self-field, whereas it increases as the number of strips increases. The influence of the 3rd HD on the transport loss is minimal at a ripple current of 1% and slightly noticeable at 2%. However, it becomes more obvious as the ripple current approaches the critical value. Remarkably, even cases with equivalent total HD show significantly higher transport losses when characterised by higher 5th HD than their counterparts with 3rd HD. This comprehensive analysis provides valuable information on the performance characteristics of HTS stacks in all-electric aircraft busbar applications and offers important insights for the development and optimisation of these systems in practical aerospace applications.

  AtıfScopus1·WoS1

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• MakaleYalnız künye2024/r/bayburt/11643
  Machine learning driven optimization and parameter selection of multi-surface HTS Maglev

  Ozkat, Erkan Caner; Abdioglu, Murat; Ozturk, U. Kemal

  This research aims to tackle the challenges posed by precise force measurement for high temperature superconducting (HTS) Maglev systems, including mechanical constraints, step motor limitations, and sensor resolutions. For this aim, six machine learning (ML) models namely Support Vector Machine (SVM), Gaussian Process Regression (GPR), Extreme Gradient Boosting (XGB), Long Short-Term Memory (LSTM), Extreme Machine Learning (EML), and Convolutional Neural Network (CNN) were developed to predict levitation force (Fz) and lateral force (Fx) based on process parameters including permanent magnet width (PMW), field cooling height (FCH), the movement in the z-axis (vertical distance), and the movement in the x-axis (lateral distance). Among six ML models, CNN emerged as the most accurate model, demonstrating smaller root mean square deviation (RMSD) without compromising correlation coefficients. Furthermore, an innovative process window approach was introduced to select process parameters that simultaneously meet the minimum value of Fz and maximum value of Fx, named β1 and β2, set at 90 N and 0 N, respectively. Within this window, PMW of 30 mm and z values less than 10 mm were found to be consistent for all FCH and x values. The novelty of this study is to formulate the optimisation problem in HTS Maglev using the developed ML model by addressing two specific objectives one of which focuses on maximizing Fz while ensuring Fx remains within a defined tolerance (β3), representing the minimum allowable ratio of the levitation force to the total force, and the second problem aims to maximize Fz while obtaining zero Fx. The optimum PMW, FCH, x, and z values were obtained at 30 mm, 30 mm, 4 mm and 5 mm, corresponding to Fz and Fx values of 224.2 N and -53.8 N for option 1. As for option 2, the process parameters were obtained as 28.6 mm, 25.9 mm, 0 mm, and 5 mm, corresponding to Fz and Fx values of 194.2 N and 0 N. It was obtained both experimentally and by the optimization that Fz reaches close its maximum as the Fx gains attractive character. Hence, it is expected that the outcomes of this study will significantly benefit the design of HTS Maglev systems and find valuable applications across various transportation engineering projects.

  AtıfScopus21·WoS18

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