Multi-objective design optimization of a permanent magnet axial flux eddy current brake

Tarvirdilu-Asl, Rasul
Yuksel, Murat
Keysan, Ozan
The main aim of this study is to optimize an axial flux eddy current damper to be used in a specific aviation application. Eddy current dampers are more advantageous compared to conventional mechanical dampers as they are maintenance-free due to contactless structure and have higher reliability, which is very desirable in aerospace applications. An initial eddy current brake prototype is manufactured and the test results are used to verify the 3-D finite element simulations. The effect of temperature on the brake performance is investigated. Finally, a multiobjective genetic algorithm optimization is applied to find the optimum pole number and geometric dimensions of the eddy current brake in order to achieve the desired torque-speed characteristic while the total weight of the brake is minimized. It is found that the mass and volume of the initial prototype can be halved by implementing this optimization algorithm.


Sensorless vector control of induction motor based on flux and speed estimation
Ertuğrul, Barış Tuğrul; Ersak, Aydın; Department of Electrical and Electronics Engineering (2008)
The main focus of the study is the implementation of techniques regarding flux estimation and rotor speed estimation by the use of sensorless closed-loop observers. Within this framework, the information about the mathematical representation of the induction motor, pulse width modulation technique and flux oriented vector control techniques together with speed adaptive flux estimation a kind of sensorless closed loop estimation technique- and Kalman filters is given. With the comparison of sensorless closed...
Triple stub circuit topology as simultaneous insertion phase, amplitude and impedance control circuit for phased array applications
Unlu, M.; Demir, Şimşek; Akın, Tayfun (Institution of Engineering and Technology (IET), 2012-10-23)
This study shows that the well-known triple stub circuit topology can also be used for controlling the insertion phase and amplitude of a given signal simultaneously, as well as preserving its impedance transformation ability. The triple stub circuit topology, which is nothing but an extension of the conventional double stub loaded-line phase shifter, results in one more degree of freedom to its solution when it is solved for its insertion phase. This additional degree of freedom not only brings the impedan...
Metasurface Lens for Ultra-Wideband Planar Antenna
Yesilyurt, Omer; Sayan, Gönül (Institute of Electrical and Electronics Engineers (IEEE), 2020-02-01)
In this article, an ultra-wideband metasurface lens is designed and integrated into an antipodal Vivaldi antenna (AVA) to improve its radiation directivity without affecting its efficiency and return loss characteristics. The metasurface lens consists of high permittivity metamaterial unit cells which resonate at frequencies far away from the operation bandwidth of 1-6 GHz. Electric field distributions of the antennas show that the near-field behaves more planar for the metasurface lens loaded AVA, as compa...
Mathematical modeling of horizontal two-phase flow through fully eccentric annuli
Ömürlü, Çiğdem; Özbayoğlu, Evren; Department of Petroleum and Natural Gas Engineering (2006)
The primary objective of this study is to understand the mechanism, the hydraulics and the characteristics, of the two-phase flow in horizontal annuli. While achieving this goal, both theoretical and experimental works have been conducted extensively. The METU-PETE-CTMFL (Middle East Technical University, Petroleum and Natural Gas Engineering Department, Cuttings Transport and Multiphase Flow Laboratory) multiphase flow loop consists of 4.84 m long eccentric horizontal acrylic pipes having 0.1143m inner dia...
A New Approach to Investigation of the Relationship of VLF Signals by Using Longitudinal Analysis Models
Guzel, E.; Yaşar, M.; Kılıç, M. B.; Canyılmaz, M. (Hindawi Limited, 2013)
Longitudinal analysis models are applied to analyze very low frequency (VLF) electromagnetic waves signals. They are useful in realization of nuance of relationship between parameters of concern which change over time. VLF data are so important for the communication and determining the disturbances in the lower ionosphere. In this study, we used a four-day VLF signal data which come from transmitter stations located at two different countries to Elazi. g receiver system. A very important feature of this dat...
Citation Formats
R. Tarvirdilu-Asl, M. Yuksel, and O. Keysan, “Multi-objective design optimization of a permanent magnet axial flux eddy current brake,” TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES, pp. 998–1011, 2019, Accessed: 00, 2020. [Online]. Available: