• 한국해양공학회지
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• 제16권1호
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• pp.58-63
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• 2002

In this research, a design guideline of current generating HAT rotor and acceptable field rotor in offshore environment is proposed. To design HAT rotor model, wind mill rotor design principles and turbine theories were applied based on a field HAT rotor experimental data. To verify the compatibility of the rotor design method and to analyze the properties of design factors, 3 rotor models were designed and experimented in a circular water channel. Three rotor models were designed according to different blade numbers and blade shapes. By changing flow velocity, rotor rpm, the rotor power and efficiency were measured and the properties of rotor were estimated. The results can be effectively applied to the design of current generation rotor.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.25-28
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• 2008

An aerodynamic calculation in hover of KUH main rotor blade is performed using a three-dimensional unstructured hybrid mesh viscous flow solver. The flow solver utilizes a vertex-centered finite-volume scheme that is based on the Roe's flux-difference splitting with an implicit Jacobi/Gauss-Seidel time integration. The eddy viscosity are estimated by the Spalart-Allmaras one-equation turbulence model. A solution-adaptive mesh refinement technique is used for efficient capturing of the tip vortex. Calculations are performed at several operating conditions with varying collective pitch setting for KUH main rotor blade in hover. Good agreements are obtained between the present and other results using HOST and CAMRAD II in overall rotor performance. It is demonstrated that the present vertex-centered flow solver is an efficient and accurate tool for the assessment of rotor performance in hover.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.57-60
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• 2003

This Paper contains the development procedure of Mach small-scaled composite rotor blade for helicopter articulated rotor system. This mach small-scaled composite blade design is conducted by using CORDAS program developed by KARI. The Dynamic analysis for an articulated rotor system with this blade is conducted by using FLIGHTLAB which is commercial software for helicopter analysis. Also the optimizing procedure of iterative design was described. The designed composite blades were manufactured after establishing the effective curing method. For small-scaled rotor test, strain gauges were embedded in composite blade spar to obtain bending & torsion strain value. To verify sectional properties of a blade, the bench test is accomplished. After comparing a designed data and tested data, Dynamic Calculation was repeated using tested data. Through this research, experiences of mach small-scaled composite blade development were accumulated and will be applied to the related research field.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.444-447
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• 2009

The optimum design and the performance analysis software called POSEIDON for the HAWT (Horizontal Axis Wind Turbine) was developed by use of BEMT. The Prandtl's tip loss theory was adopted to consider the blade tip loss. The aerodynamic characteristics of NACA 63415 airfoils were predicted via X-FOIL and the post stall characteristics were estimated by the Viterna's equations. All the predicted aerodynamic characteristics are fairly well agreed with the Velux wind tunnel test results. The rated power of the testing rotor is 5kW at design conditions. The power, estimated by use of predicted lift and drag coefficient via X-FOIL becomes a little higher than experimental one.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.492-492
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• 2009

Nowadays in Republic of Korea, there is no distinct reference for the related design technology of rotor blade of wind turbine. Therefore the optimum design and evaluation of performance is carried out with foreign commercial code softwares. This paper shows in-house code software that evaluates the aerodynamic design of wind turbine rotor blade using blade element-momentum theory (BEMT) and processes that is applied through various aerodynamics theories such as momentum theory, blade element theory, prandtl's tip loss theory and strip theory. This paper presents the results of the numerical analysis such as distribution of aerodynamic properties and performance curves using in-house code POSEIDON.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.71-74
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• 2012

Generally, tone noise is generated at the rotary wing and helicopter. BVI(Blade-Vortex Interaction) noise is one of the helicopter's tone noise. The BVI noise is governed by tip-vortex characteristics such as vortex size, strength and trajectory. To avoid BVI, many methods have been developed and proposed. In this paper, rotating blade with active tab was numerically investigated to reduce BVI noise. For flow and noise simulation, the lifting surface approach and the acoustic analogy were used. Using numerical methods, the noise directivity and maximum noise position were predicted.

• 한국항공운항학회지
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• 제14권4호
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• pp.11-16
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• 2006

The wind turbine rotor blade is faced with various aeroelastic problem as rotor blades become bigger and lighter by the use the composite material. The aeroelastic analysis of a wind turbine rotor blade requires its aerodynamic model and structural model. For effective aeroelastic analysis, it is required the simple and effective structural model of the blade. In the present study, we introduce the effective equivalent structural modeling of the blade for aeroelastic analysis. The equivalent beam model of the composite blade based on its 3D finite element model is established. The free vibration analysis shows that the equivalent beam model of the blade is equivalent to its 3D finite element model.

• 항공우주기술
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• 제3권1호
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• pp.35-44
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• 2004

본 연구에서는 액체로켓에 쓰이는 터보펌프 부분흡입현 터빈의 1차원 공력계산 및 구조설계에 대해 고찰하였다. 터빈은 노즐, 로터, 후방유도익등으로 나누어 각각에 대해 공력 특성을 계산식으로부터 유도하였고 CFD 계산을 통해 그 타당성을 입증하였다. 속도삼각형과 같은 1차원 설계 변수들은 평균선 방정식을 이용하여 수행되었고 2-D, 3-D CFD 계산을 통해 보정되었다. 블레이드 익형은 CFD 최적화기법을 통해 결정되었다. 향후, 열응력계산, 구조응력계산을 통한 열적/구조적 거동에 대해 연구가 필요하다.

• 한국태양에너지학회 논문집
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• 제28권1호
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• pp.25-32
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• 2008

Aeroelastic phenomena of a wind turbine include stall-induced vibrations and classical flutters. The classical flutter occurs due to coalescence between bending mode and torsion mode. It is typically the aeroelastic instability of an aircraft wing. Different from the classical flutter, the stall-induced vibration is the instability in lead-lag mode due to negative aerodynamic dampings. In the present study, the three degree of freedom aeroelastic model of a wind turbine blade is introduced to characterize and analyze its aeroelastic phenomena. The numerical results show that the aeroelastic stability of flap-lag motion is more unstable than that of flap-pitch motion and the aeroelastic characteristics of lead-lag motion can become unstable as wind speed increases.

• 항공우주시스템공학회지
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• 제8권3호
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• pp.41-46
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• 2014

Fatigue evaluations for the rotor blades of commercial or military rotorcraft have been carried out using the safe life concept since 1950s. Particularly, in the case of a rotor blade made of a composite material, a highly reliable fatigue life could be predicted by evaluation the cumulative damage using combination of fatigue life curve and load spectrum. However, there is a limit in adequately evaluating the strength reducing phenomena caused by damages or defects generated during the manufacturing process or impact damage induced by operational usages, using only the safe life concept. In this study, the fatigue evaluation process based on the damage tolerance concept is described and illustrated by means of successful application to substantiate the retirement time of composite rotor blades.