• Title/Summary/Keyword: 주날개

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Improvement of the Flow Characteristics by Optimizing the Leading-Edge Shape Around Airfoil/Flat-Plate Junction (날개-평판 접합부에서의 날개 앞전 형상 최적화를 통한 유동특성 향상)

  • Cho, Jong-Jae;Kim, Kui-Soon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.6
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    • pp.24-33
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    • 2009
  • The present study deals with the optimization of the leading edge shape around a wing-body junction to minimize the strength of the horseshoe vortex, which is one of the main factor generating the secondary flow losses. For this purpose, approximate optimization method is used for the optimization. The study is performed by using $FLUENT^{TM}$ and $iSIGHT^{TM}$. The total pressure coefficient for the optimized model was decreased about 9.79% compared with the baseline model.

Improved Operation Criteria for a Power Generation Gas Turbine on the Blade Path Temperature Variations (날개통과온도 변화에 기반한 발전용 가스터빈의 운전관리 개선)

  • Yong-Il Lee;Jae-Heon Lee
    • Plant Journal
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    • v.18 no.4
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    • pp.48-57
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    • 2023
  • In this study, I discussed a way of the improved operation criteria to detect combustion instability in advance F-Class Gas Turbine, which adopts lean pre-mixed combustion system. The data of 16 blades path temperature thermocouple installed radially at the gas Turbine exit were collected to analyze the variation of individual blade path temperature. The cumulative variation in individual blade path temperature for one week under normal combustion conditions was confirmed to be up to 26℃. On the other hand, in the event of combustion instability, the symptoms of increased temperature variations in the individual thermocouple were mostly seen from a few days ago. Based on the results of this study, it is deemed appropriate to inspect and maintain in Ulsan Thermal Power Gas Turbine when the individual blade path temperature exceeds 50℃ of the cumulative variation for 10 days.

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A Comparison of Aerodynamic Prediction Methodologies for Missile Configurations (유도무기 형상의 공력 특성 예측 방법 비교)

  • Noh, Kyung-Ho;Kang, Donggi;Kim, Jaehyun;Kim, Young Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.11
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    • pp.755-762
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    • 2022
  • The wind tunnel test data for the missile configuration were compared with analysis results using various semi-empirical code and CFD analysis code. The three types of configurations were used for comparison including 2 types of main wing, inline and interdigitate configuration that the main wing and tail intersect. Additionally, it was confirmed that the vortex flow was accurately predicted by comparing the CFD analysis result with the flow visualization test result.

A Study of Multi-point Numerical Optimization Design for Transonic Airfoils (천음속 날개꼴의 Multi-point 수치최적화 설계에 관한 연구)

  • 손명환;권성재
    • Journal of the Korea Institute of Military Science and Technology
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    • v.1 no.1
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    • pp.145-153
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    • 1998
  • In the direct numerical optimization method, the aerodynamic coefficients of the airfoil designed by one-point design can be deteriorated at other operating points. Therefore, the capacity of the multi-point design is indispensable for actual airfoil design. In this paper, the two-point design of transonic airfoils is studied based on the Navier-Stokes equations flow solver and the feasible direction optimization algorithm, and the effects of weighting parameter were analyzed and compared. The results show that the airfoils designed by two-point design satisfy the performances at the peripheral regions of two operating points concurrently and have the favorable aerodynamic characteristics at the point which has larger weighting parameter than the other point.

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Feeding habits of Favonigobius gymnauchen in the eelgrass (Zostera marina) bed in Kwangyang Bay (광양만 잘피밭에 서식하는 날개망둑 (Favonigobius gymnauchen)의 식성)

  • HUH Sung-Hoi;KWAK Seok Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.3
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    • pp.372-379
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    • 1998
  • Feeding habits of Favonigobius gymnauchen collected from the eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. Favonigobius gymnauchen was a carnivore which consumed mainly gammarid amphipods, polychaetes, crabs and copepods. Its diets included minor Quantities of gastropods, tanaids and isopods. It showed ontogenetic changes in feeding habits. Small individuals (1$\~$2 cm) fed mainly on gammarid amphipods, polychaetes, and copepods. While the portion of the stomach contents attributable to polychaetes and crabs increased steadily with incensing fish size, consumption of copepods decreased progressively. Gammarid amphipods were the most selected prey item for all size classes. Although gammarid amphipods, polychaetes, crabs and copepods were major prey organisms for all seasons, the relative proportion of these food items changed with season. Consumption of copepods was relatively high in spring and fall and consumption of gammarid amphipods, polychaetes and crabs was relatively high in summer.

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Hydrodynamic Aspects on Three-dimensional Effects of Vertical-axis Tidal Stream Turbine (조류발전용 수직축 터빈의 유체동력학적 3차원 효과에 관한 연구)

  • Hyun, B.S.;Lee, J.K.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.2
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    • pp.61-70
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    • 2013
  • Hydrodynamic aspects on three-dimensional effects were investigated in this study for simple and convenient conversion of tidal stream energy using a Vertical-Axis Turbine (VAT). Numerical approach was made to reveal the differences of flow physics between 2-D estimation and rigorous 3-D simulation. It was shown that the 3-D effects were dominant mainly due to the variation of tip vortices around the tip region of rotor blade, causing the loss of lift for steadily translating hydrofoil and the reduction of torque for rotating turbine blade. The 3-D effect was found to be rather prominent for the typical VATs considered in this paper. Simple and yet efficient 2-D approach with the correction of its three-dimensionality was also proposed for practical design and analysis of VAT.

산업 - 회원사 탐방 - 현항공산업(주)

  • 한국항공우주산업진흥협회
    • Aerospace Industry
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    • s.108
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    • pp.36-39
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    • 2010
  • 올해로 창사 22주년을 맞은 현항공산업(주), 부산 녹산공단에 위치하고 있는 이 회사는 항공기 날개 제작 및 동체부품 등을 최상의 품질로 생산함으로써 항공기부품 가공 기업의 선도적 역할을 하고 있는 중소기업으로 주목 받고 있다.

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공대공 미사일의 알파와 오메가

  • 한국항공우주산업진흥협회
    • Aerospace Industry
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    • v.55
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    • pp.62-65
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    • 1997
  • 대개 전투기의 사진을 보면 주날개 양쪽 끝에 가늘고 긴 미사일이 한발씩 달려 있다. 그리고 전투기 배쪽에도 같은 것이 장착되어 있다. 무엇일까? 바로 공대공 미사일이다. 즉 하늘에서 적 전투기를 만나 공중전에 들어 갔을 때 적기를 향하여 쏘는 적외선 열추적 미사일인 것이다.

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Surface pressure measurement on a wing of SWIM by using PSP (PSP를 이용한 항공기 형상 모형 날개 표면 압력 측정)

  • Jung, Hye-Jin;Kwon, Kijung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.4
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    • pp.337-345
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    • 2008
  • this study, three dimensional surface pressure distributions of SWIM whose main wing has NACA4412 airfoil with NACA0012 flaps were experimentally measured by pressure sensitive paint. Surface pressures on suction and pressure sides of the wing were measured by changing an angle of attack at a Reynolds number of 3.1x105 in KARI 1m subsonic wind tunnel. The experimental results showed that as an angle of attack increases minimum pressure region on a suction side moved from the wing root to the tip and low pressure region around trailing edge of the wing tip which causes wing tip vortex was observed. Although low pressure region at the tip still observed at an angle of attack 15 deg., other area on a suction side showed flat pressure distribution in a span-wise direction. It was also observed that the mean value of pressure coefficients was about 0.077 through a comparison between PSP and pressure taps at the same test conditions.

Velocity Field Measurements Over A Lex/Delta Wing By Triple Axis Hot-Film Anemometry (3축 HOT-FILM 풍속계에 의한 연장된 앞전을 갖는 삼각날개 속도장의 측정)

  • Lee,Gi-Yeong;Son,Myeong-Hwan;Jang,Yeong-Il
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.9
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    • pp.1-8
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    • 2003
  • Velocity data were acquired at a series of stations in the chordwise direction above a delta wing with leading edge extension, using a triple axis hot film anemometry. Surveys normal to planform yield velocity field data at incidence angle of 24$^{\circ}$and 32$^{\circ}$at a centerline chord Reynolds number of $1.76{\times}10^6$. Experimental results of velocity measurements of mean velocity of three components gave a confidence to quantitative investigate the vortical flow field over a LEX-delta wing with this probe. The present experiments indicated the existence of both wing and LEX vortex where the local mean axial velocity is maximum. It also shown the development of secondary vortex of opposite sign of rotating above the wing surface near the leading edge. The insertion of probe across the flow field was found to have little influence on the position of the vortex core.