https://scholarworks.gnu.ac.kr/handle/sw.gnu/564 Mon, 16 Mar 2026 21:21:54 GMT 2026-03-16T21:21:54Z https://scholarworks.gnu.ac.kr/handle/sw.gnu/81272 Title: Quasi-3D를 활용한 극 수 변화에 따른 저속 고토크 AFPM 모터의 경향성 연구 Authors: 전상률; 김규섭 Abstract: This study analyzes the performance of a low-speed, high-torque axial flux permanent magnet (AFPM) motor for different pole and slot numbers using a quasi-three-dimensional (3D) method. The AFPM motor has a single-stator, double-rotor configuration, where the radial direction is divided into N layers. Two-dimensional analyses are conducted for each layer. The results are integrated to approximate 3D effects. The average torque, induced voltage, no-load back electromotive force, and efficiency characteristics are compared for various pole/slot combinations considering copper and iron losses. In addition, the performance variations due to changes in the pole and slot numbers are quantitatively evaluated. The average error between the quasi-3D finite element analysis (FEA) and 3D FEA results is approximately 2.77%, thereby verifying the accuracy of the proposed method. The 24-pole/36-slot configuration demonstrates the best performance within the considered design range. These results indicate that the quasi-3D method is effective in the preliminary design stage. Furthermore, it can serve as a useful guideline for pole and slot number optimization in AFPM motors for low-speed, high-torque applications. Sat, 01 Nov 2025 00:00:00 GMT https://scholarworks.gnu.ac.kr/handle/sw.gnu/81272 2025-11-01T00:00:00Z https://scholarworks.gnu.ac.kr/handle/sw.gnu/79716 Title: 자동차용 수소 차단밸브의 구조적 안정성 평가 Authors: 김나용; 김문학; 이치우 Abstract: This study evaluates the structural stability of a hydrogen shut-off valve used in fuel cell electric vehicles (FCEVs) under extreme operating conditions, including high pressure and cryogenic temperatures. Using a one-way Fluid-Structure Interaction (FSI) analysis based on ANSYS CFX and Static Structural, the study simulates thermal and pressure loads on key components. The results show that the maximum equivalent stress occurs in the rod (361.22 MPa), while safety factors for all components remain above 2.11, confirming adequate structural integrity. In order to secure higher structural stability and reduce the weight of parts, attention should be paid to the selection of materials and improving the shape. The findings provide a valuable basis for improving the design reliability and optimization of hydrogen shut-off valves for future automotive applications. The leak tightness and durability tests of the hydrogen shut-off valve under cryogenic conditions verified its structural integrity, confirming its safety even after more than 5.2 million repeated operations. Fri, 01 Aug 2025 00:00:00 GMT https://scholarworks.gnu.ac.kr/handle/sw.gnu/79716 2025-08-01T00:00:00Z https://scholarworks.gnu.ac.kr/handle/sw.gnu/79643 Title: 표면 가공 후 목재 종류별 표면거칠기 비교분석에 관한 연구 Authors: 이해진; 공정리; 김해지 Abstract: Wood surface processing is a crucial step in determining final product quality. Because wood surface treatment methods can significantly affect the durability, appearance, and texture of products, understanding the optimal processing methods for different types of wood is crucial. Sanding, including the process of gradually smoothing the surface using sandpaper of various grits, is a core process that controls the roughness of the wood surface and improves the finishing quality. This study aims to analyze the changes in the surface characteristics of walnut and ash wood under various sanding conditions. Specifically, by comparing and analyzing the differences in surface roughness and strength in the longitudinal and transverse directions of the wood, we intend to derive the optimal processing direction and conditions for each type of wood. Tue, 01 Jul 2025 00:00:00 GMT https://scholarworks.gnu.ac.kr/handle/sw.gnu/79643 2025-07-01T00:00:00Z https://scholarworks.gnu.ac.kr/handle/sw.gnu/79587 Title: 조향기어박스의 랙 앤 피니언 강도 개선방안에 관한 연구 Authors: 장성수; 장정환; 김해지; 백상훈 Abstract: This study aims to develop a rack and pinion gear based power steering gearbox for the Korean multiple launch rocket system(K-MLRS). The K-MLRS is a military vehicle requiring high speed maneuverability and precise steering control over rough terrain. However, conventional manual steering systems impose significant operational burdens and exhibit limited durability. In particular, the rack and pinion gears, which are critical components of the steering mechanism, require design optimization and durability improvements. To enable the design of an optimized rack and pinion structure, this study analyzes the lifespan of a rack and pinion gear based on tooth profile modifications. Furthermore, gear optimization, contact stress analysis, and durability evaluations were conducted. Tue, 01 Jul 2025 00:00:00 GMT https://scholarworks.gnu.ac.kr/handle/sw.gnu/79587 2025-07-01T00:00:00Z