WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Semi Analytical Study and Calculation of Magnetic Flux Density Created by Rectangularly Shaped Planar Coils With Rounded Corners(Springer int Publ Ag, 2025-04-25) Kilic, Veli Tayfun; Kavuncu, UmutIn this paper, magnetic flux density induced by a rectangularly shaped single-turn planar coil with rounded corners is investigated. Starting from Biot-Savart law analytical derivations are obtained and contributions of straight edges and rounded corners of a coil to a flux density at a point in a three-dimensional space are formulated. In the derived formula the magnetic flux density generated by a coil with rounded corners is expressed as a function of the coil's geometrical parameters including start and end points of the roundings together with the center of the circles that contain arcs at the corners and observation point coordinates. Magnetic flux density distribution of rectangular coils with different sizes and roundings at the corners were calculated on distinct planes by using the derived formula. Also, FEM based electromagnetic simulations and measurements were done for the same coils. The results obtained in the analytical calculations, FEM calculations and measurements are in a good agreement.Article Citation - WoS: 1Citation - Scopus: 1Investigating the Tradeoff Between the MMF Distortion and End Turn Length of a 2-Pole Line Start SynRM Performance(Springer int Publ Ag, 2023-07-19) Tekgun, Didem; Cosdu, Muhammed M.; Tekgun, Burak; Alan, IrfanConventional 2-pole AC machine windings have long end windings and generate harmonics, which increase losses and reduce torque density. This study investigates the performance tradeoff between the level of distortion (THD) in winding magneto-motive force (MMF) and end turn length on a 2-pole line start Synchronous Reluctance Machine (LS-SynRM) machine. A two-stage approach is used, winding and geometry optimization. Various multilayer winding configurations having unevenly distributed number of turns are investigated. First, the percentage of the turns in a coil group is optimized for minimum harmonics and end turn length for all structures. Second, geometric optimization is performed on selected winding configurations. Sixteen different configurations are optimized, and Pareto optimal solutions are obtained. Later, these solutions are graded with a new score-based assessment method to quantify the quality of the results. It is concluded that the designs having lower THD in winding MMF perform better than the designs with shorter end turns in terms of efficiency and torque density.Article Citation - WoS: 4Citation - Scopus: 4Experimental Investigation of Soil Disturbance Effect on Bearing Capacity of Organic Soil(Springer int Publ Ag, 2023-10-11) Cadir, Cenk Cuma; Kaya, Zulkuf; Yalcin, Hakan; Erol, Aykut; Uncuoglu, Erdal; Akin, MugeThe model test investigations on the soft soils are usually carried out on samples prepared in the laboratory and assuming site conditions. However, such soils that are prepared in the laboratory only partially reflect the site conditions. Considering this gap in the literature, this study mainly focuses on the bearing capacity and settlement behavior of the undisturbed organic soil obtained by a novel block sampling technique. The disturbed organic soil prepared in the laboratory was investigated with large-scale model experiments for two different footing types (square and rectangular). Vane Shear testing (VST), Dynamic Cone Penetration (DCP) tests, and finite-element analysis (FEA) were performed. The average bearing capacity values of disturbed and undisturbed soil were 60.98 kPa-68.71 kPa and 108.18 kPa-110.89 kPa for square and strip footings, respectively. Bearing capacity reductions of up to 40% were determined on laboratory-prepared soils. The cone reached the required depth (450 mm) with three blows for disturbed soil, while it was reached with four blows for undisturbed soil. Likewise, the undrained shear strength obtained by the VST was determined as 22.16 kPa and 16.60 kPa for undisturbed and disturbed soils, respectively. Shear strength losses of up to 25% for disturbed soils were observed. The bearing capacity values obtained from FEA were comparable to those obtained with the model tests. It was concluded that the degree of degradation of organic soils in the laboratory significantly affects the bearing capacity of the soil.Article Citation - WoS: 4Citation - Scopus: 4Characterization of Limestone Calcined Clay Cement Made With Calcium Sulfoaluminate Clinker(Springer int Publ Ag, 2024-07-02) Atasever, Muhammet; Erdogan, Sinan TurhanThis study concentrated on producing limestone calcined clay calcium sulfoaluminate cement by replacing portland cement in limestone calcined clay cement with calcium sulfoaluminate cement, with the goal of increasing the early strength of limestone calcined clay cement. The mineralogy and microstructures of hydrating pastes were investigated using x-ray diffraction and scanning electron microscopy. Heat evolution was studied using isothermal calorimetry. Strength development and workability were assessed on mortar samples. The 1 day strengths of limestone calcined clay calcium sulfoaluminate cement samples exceeded those of limestone calcined clay cement by similar to 30-80%, though its strength gain slows significantly after 1 day due to the lack of calcium silicates, affecting pH and clay dissolution. Despite this, the strength development of limestone calcined clay calcium sulfoaluminate cement, when adjusted for CO2 emissions, is comparable to limestone calcined clay cement. Additionally, limestone calcined clay calcium sulfoaluminate cement provides a 10-15% higher flow and exhibits a lower heat of hydration beyond 12 h, while maintaining a production cost similar to that of limestone calcined clay cement.