보조 동력 장치 연료 공급용 서보밸브의 토크모터 전자기 해석

장세명,장강원,정헌술,이동호,Chang, Se-Myong,Jang, Gang-Won,Jeong, Heon-Sul,Rhee, Dong-Ho 항공우주시스템공학회 2007 항공우주시스템공학회지 Vol.1 No.3

As a main part of an utility helicopter, the APU(Auxiliary Power Unit) has a solenoid valve system operated with a torque motor, which controls the flow rate in the fuel supply system. In this paper, we solved the Maxwell potential equations to analyze the electromagnetic force in the torque motor, and some additional analytic methods are used to compute the quantity of torque produced by the torque motor for the given circuit current. For the convenience, small displacement is assumed, and only magneto-static problem is considered for the two-dimensional cross section. The result will be compared with the three-dimensional analysis that will be studied in the near future.

10 ㎾급 수평축 풍력 터빈 로터 블레이드의 공력 설계

장세명(Se-Myong Chang),이장호(Jang-Ho Lee) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.10

10 ㎾급 수평축 풍력 터빈의 로터를 개발하기 위해 블레이드의 공력 설계 절차를 체계적으로 연구하고 실행하였다. 운동량 이론과 깃 요소법에 근거한 역 설계 방법을 확립하고, 이를 이용하여 주어진 공력 분포에 따른 근사 최적 형상을 설계하였다. 설계된 형상은 공군사관학교의 풍동에서 검증되었고, 본 설계를 통하여 실제로 제작된 로터로부터 실측데이터를 취득하여 비교하였다. 본 연구를 통하여 저자들은 용력 터빈 블레이드의 설계 방법에 대한 체계적 기술을 축적하고, 나아가 같은 방법을 중대형 시스템으로 확장하기 위한 기술적 노하우를 취득하였다. The procedure for the aerodynamic design of the rotor blades for 10 ㎾-level HAWT(horizontal axis wind turbine) has been investigated to be practiced systematically. The approximately optimal shape was designed using an inverse method based on the momentum theory and the blade element method. The configuration was tested in the wind tunnel of the Korea Air Force Academy, and the data was compared with those obtained from the real system manufactured from the present design. From this research, the authors established the systematic technology for wind turbine blades, and set up the technical procedure which can be extended for the future design of middle and large sized wind turbines.

초소형 풍력발전용 블레이드에 대한 구조설계 몇 해석

이승표,강기원,장세명,이장호,Lee, Seung-Pyo,Kang, Ki-Weon,Chang, Se-Myong,Lee, Jang-Ho 한국생산제조학회 2010 한국생산제조학회지 Vol.26 No.2

In recent years, wind energy has been the world's fastest growing source of energy. This paper describes the structural design and analysis of composite blade for 2 kW-level HAWT (horizontal axis wind turbine). The aerodynamic design and force, which are required to design and analyze a composite blade structurally, are calculated through BEMT(blade element momentum theory) implemented in public code PROPID. To obtain the equivalent material properties of filament wound composite blades, the rule-of-mixture is applied using the basic material properties of fiber and matrix, respectively. Lay-up sequence, ply thickness and ply angle are designed to satisfy the loading conditions. Structural analysis by using commercial software ABAQUS is performed to compute the displacement and strength ratio of filament wound composite blades.

한국형 소형 풍력 블레이드 개발에 관한 연구

이장호(Lee, Jang-Ho),장세명(Chang, Se-Myong),김상진(Kim, Sang-Jin) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.11

To get the better efficiency in Korean type wind characteristics, a new wind turbine blade was developed with some structural, vibrational, and aero-elastic analysis for the design of the full-scale blade. A series of full domestic technology from design to manufacturing was created and used in the middle of the development of nelv wind blade. And it was equipped and measured at the wind test side in the Jeju island. After test, it is verified that the blade has the regular capacity of 10kW at the air velocity of 10m/s. And it shows better capacity in the low air-velocity compared to the imported blade. therefore it can be made by only domestic technology, and used for the domestic wind distribution with the better power generation.

P1 비순응 유한요소를 이용한 Navier-Stokes 유동 문제의 위상최적화

장강원(Gang-Won Jang),장세명(Se-Myong Chang) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

An alternative approach for topology optimization of Navier-Stokes flow problems is presented by using P1 nonconforming finite elements. Due to the discrete divergence-free property of the P1 nonconforming element, the continuity equation of flow can be imposed by using the penalty method into the momentum equation. So, instead of using the mixed formulation, the velocity-only formulation can be built and thus numerical expense for optimization can be efficiently reduced. Moreover, while nodes of other quadrilateral nonconforming elements are mostly located at the midpoints of element edges, the present P1 nonconforming elements have vertex-wisely defined degrees of freedom, so its implentation is as simple as the standard bilinear conforming elements. The effectiveness of the proposed formulation is verified by showing examples with various Reynolds numbers.

증기발생기 전열관의 마멸 손상에 관한 연구 동향

이신영(Sin-Young Lee),장세명(Se-Myong Chang),장강원(Gang-Won Jang) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.5-3

Steam Generator tube is a place where the first system and the second system meet. The first coolant system flows inner side of multiple steam generator tube transfer heat to second coolant system. Fracture of steam generator tube is one of main accident which are considered during design stage of a power plant and important for safe operation of a power plant. There have been many studies for the wear damage of steam generator tubes of power plant and wear due to vibration of tubes are important in the studies of tube wear damage.

P1 비순응 요소를 이용한 비압축성 유동 문제의 위상최적화

장강원(Gang-Won Jang),장세명(Se-Myong Chang) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.10

P1 비순응 요소를 이용하여 정상 비압축성 Navier-Stokes 유동의 위상최적화 문제를 푸는 방법을 제시한다. 본 연구는 Stokes 유동의 위상최적화 문제에 P1 비순응 요소를 적용하여 그 수치적 효용성을 보인 바 있는 이전 연구에 대한 후속 연구이다. 비압축성 물질 해석에서 잠김현상이 발생하지 않으며 선형 형상함수를 가지는 P1 비순응 요소의 장점이 관성항을 가지는 유체 문제의 해석과 설계에도 유효한 지를 파악하고자 한다. 일반적으로 사용되는 혼합정식화법과 비교하여 P1 비순응 요소의 사용은 벌칙 함수를 이용하여 연속 방정식을 따로 사용하지 않고 운동방정식에 부과할 수 있기 때문에 자유도의 개수를 감소시킬 수 있다. 벌칙 파라미터가 해의 정확도에 주는 영향과 적정 범위는 수치적으로 검토하도록 한다. 또한 보통의 사각 비순응 요소들이 요소면의 중앙에 절점을 가지고 고차의 형상함수를 지니는데 비하여, 본 연구에서 제시하는 P1 비순응 요소는 요소의 꼭지점에 절점을 가지고 {1, x, y}의 P1 형상함수로 구성됨으로써 수치적인 구현의 용이함이 일반 선형 사절점 요소와 동일하다. 제안한 방법의 효용성을 다양한 레이놀즈수에 따른 유동최적화 문제들을 살펴봄으로써 검증하도록 한다. An alternative approach for topology optimization of steady incompressible Navier-Stokes flow problems is presented by using P1 nonconforming finite elements. This study is the extended research of the earlier application of P1 nonconforming elements to topology optimization of Stokes problems. The advantages of the P1 nonconforming elements for topology optimization of incompressible materials based on locking-free property and linear shape functions are investigated if they are also valid in fluid equations with the inertia term. Compared with a mixed finite element formulation, the number of degrees of freedom of P1 nonconforming elements is reduced by using the discrete divergence-free property; the continuity equation of incompressible flow can be imposed by using the penalty method into the momentum equation. The effect of penalty parameters on the solution accuracy and proper bounds will be investigated. While nodes of most quadrilateral nonconforming elements are located at the midpoints of element edges and higher order shape functions are used, the present P1 nonconforming elements have P1, {1, x, y}, shape functions and vertex-wisely defined degrees of freedom. So its implentation is as simple as in the standard bilinear conforming elements. The effectiveness of the proposed formulation is verified by showing examples with various Reynolds numbers.

항공기 소음 환경 기준 설정을 위한 연구

김선우(Kim, Sun-Woo),장길수(Jang, Gil-Soo),이수갑(Lee, Soo-Gab),송민정(Song, Min-Jeong),장세명(Chang, Se-Myong),전지현(Jeon, Ji-Hyun),안병옥(Ahn, Byung-Og) 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.6

Rating scales for environmental noise are varied in their calculation procedure. Among them WECPNL (weighted equivalent continuous perceived noise level) is the rating scale for aircraft noise currently being used in domestic and applied only for aircraft noise. However $L_{dn}$ calculated from $L_{eq}$ $L_{eq}$ is used as a rating scale for not only aircraft noise but also environmental noise. Besides, it is easy to calculate and internationally preferred. It is, therefore, not adequate for the evaluation of residents' exposure. Moreover it is very difficult to measure the aircraft noise by WECPNL due to the complicated calculating procedures if automatic measuring system is not used. Accordingly. this study aims to propose alternative evaluation procedure for the aircraft noise. To achieve this purpose, the data measured by automatic measuring system were gathered and calculated with three evaluation procedures : WECPNL $L_{eq}$ and $L_{dn}$, and the results calculated from different methods were compared and analyzed.

1.5㎾급 풍력발전기용 블레이드의 구조해석 및 구조시험

김홍관(Hong-Kwan Kim),이장호(Jang-Ho Lee),장세명(Se-Myong Jang),강기원(Ki-Weon Kang) 한국유체기계학회 2010 한국유체기계학회 논문집 Vol.13 No.4

초소형 풍력발전용 블레이드에 대한 구조설계 및 해석

이승표(Seung-Pyo Lee),강기원(Ki-Weon Kang),장세명(Se-Myong Chang),이장호(Jang-Ho Lee) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.2

In recent years, wind energy has been the world's fastest growing source of energy. This paper describes the structural design and analysis of composite blade for 2 kW-level HAWT (horizontal axis wind turbine). The aerodynamic design and force, which are required to design and analyze a composite blade structurally, are calculated through BEMT(blade element momentum theory) implemented in public code PROPID. To obtain the equivalent material properties of filament wound composite blades, the rule-of-mixture is applied using the basic material properties of fiber and matrix, respectively. Lay-up sequence, ply thickness and ply angle are designed to satisfy the loading conditions. Structural analysis by using commercial software ABAQUS is performed to compute the displacement and strength ratio of filament wound composite blades.