scholarly journals Self-Synchronized Phenomena Generated in Rotor-Type Oscillators: On the Influence of Coupling Condition between Oscillators

2008 ◽  
Vol 2 (3) ◽  
pp. 861-873 ◽  
Author(s):  
Yasuhiro BONKOBARA ◽  
Hiroki MORI ◽  
Takahiro KONDOU ◽  
Takashi AYABE
Keyword(s):  
Coupling Condition ◽  
Rotor Type

Flight Control of a Twin-Rotor Type Model Helicopter Based on First-Order Approximate Linearization

2014 ◽  
Vol 134 (9) ◽  
pp. 1269-1270 ◽  
Author(s):  
Hiroki Noma ◽  
Shun Tanabe ◽  
Takao Sato ◽  
Nozomu Araki ◽  
Yasuo Konishi
Keyword(s):  
Flight Control ◽  
Type Model ◽  
First Order ◽  
Model Helicopter ◽  
Approximate Linearization ◽  
Twin Rotor ◽  
Rotor Type

scholarly journals Iron Loss Analysis of a Concentrated Winding Type Interior Permanent Magnet Synchronous Motor with Single and Dual Layer Magnet Shape

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 74
Author(s):  
Chan-Ho Baek ◽  
Hyo-Seob Shin ◽  
Jang-Young Choi
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Homogenization Method ◽  
Iron Loss ◽  
Frequency Separation ◽  
Permanent Magnet Synchronous Motors ◽  
Loss Analysis ◽  
Iron Losses ◽  
Interior Permanent Magnet ◽  
Rotor Type

In this study, the iron losses of high flux density concentrated winding-type interior permanent magnet synchronous motors for three different magnet shapes (single-V, single-flat, and dual-delta) and rotor structures are analyzed and compared. Iron loss is analyzed using the classical Steinmetz equation (CSE) based on the frequency separation approach using the iron loss material table, and each rotor type is compared. In addition, to validate the hysteresis loss for each rotor type, two additional analyses are performed. In the methods considered, the number of minor loops is counted, and the area is calculated based on DC bias. The eddy current loss is compared using two approaches: CSE base frequency separation and the homogenization method considering the skin effect. This study primarily focuses on the comparison of relative iron losses based on different rotor topologies instead of absolute comparisons.

scholarly journals Dependence of Power Characteristics on Savonius Rotor Segmentation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2912
Author(s):  
Krzysztof Doerffer ◽  
Janusz Telega ◽  
Piotr Doerffer ◽  
Paulina Hercel ◽  
Andrzej Tomporowski
Keyword(s):  
High Wind ◽  
Horizontal Axis Wind Turbine ◽  
Savonius Rotor ◽  
Power Characteristics ◽  
Wind Speeds ◽  
Single Segment ◽  
High Elongation ◽  
Low Wind Speeds ◽  
Number Of Segments ◽  
Rotor Type

Savonius rotors are large and heavy because they use drag force for propulsion. This leads to a larger investment in comparison to horizontal axis wind turbine (HAWT) rotors using lift forces. A simple construction of the Savonius rotor is preferred to reduce the production effort. Therefore, it is proposed here to use single-segment rotors of high elongation. Nevertheless, this rotor type must be compared with a multi-segment rotor to prove that the simplification does not deteriorate the effectiveness. The number of segments affects the aerodynamic performance of the rotor, however, the results shown in the literature are inconsistent. The paper presents a new observation that the relation between the effectiveness of single- and multi-segment rotors depends on the wind velocity. A single-segment rotor becomes significantly more effective than a four-segment rotor at low wind speeds. At high wind speeds, the effectiveness of both rotors becomes similar.

scholarly journals High-Q-Factor Tunable Silica-Based Microring Resonators

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 256
Author(s):  
Yue-Xin Yin ◽  
Xiao-Pei Zhang ◽  
Xiao-Jie Yin ◽  
Yue Li ◽  
Xin-Ru Xu ◽  
...  
Keyword(s):  
Optical Communications ◽  
Microring Resonator ◽  
Microring Resonators ◽  
Q Factor ◽  
Notch Depth ◽  
Critical Coupling ◽  
Practical Application ◽  
Coupling Condition ◽  
High Q ◽  
Racetrack Resonator

A high-Q-factor tunable silica-based microring resonator (MRR) is demonstrated. To meet the critical-coupling condition, a Mach–Zehnder interferometer (MZI) as the tunable coupler was integrated with a racetrack resonator. Then, 40 mW electronic power was applied on the microheater on the arm of MZI, and a maximal notch depth of about 13.84 dB and a loaded Q factor of 4.47 × 106 were obtained. The proposed MRR shows great potential in practical application for optical communications and integrated optics.

scholarly journals Polarization-Independent Circulator Based on Composite Rod of Ferrite and Plasma in Photonic Crystal Structure

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 381
Author(s):  
Mi Lin ◽  
Lixin Fu ◽  
Shakeel Ahmed ◽  
Qiong Wang ◽  
Yaoxian Zheng ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Large Scale ◽  
Optimization Method ◽  
Coupling Condition ◽  
High Isolation ◽  
Optimum Parameters ◽  
Composite Rod ◽  
Polarized Waves ◽  
Two Dimensional Photonic Crystal ◽  
Polarization Independent

We propose a type of polarization-independent circulator based on a composite rod of ferrite and plasma materials in a two-dimensional photonic crystal (PhC) slab. Only one composite rod was set at the center of the structure to provide circulation for both TE- and TM-polarized waves. Additionally, to improve the performance of the circulator, three additional rods were inserted to improve the coupling condition between the center magneto-optical microcavity and the corresponding waveguides. Finite element method was used to calculate the characteristics of the structure and the Nelder–Mead optimization method was employed to obtain the optimum parameters. The results show that a low insertion loss (~0.22 dB) and high isolation (~14 dB) can be achieved in our structure for waves of both TE and TM polarizations. The idea presented here may be useful for designing compact polarization devices in large-scale integrated photonic circuits.

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