• Title/Summary/Keyword: Drag Polar Curves

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Canard-Leading Edge Flap Scheduling for the Maneuverability Enhancement of a Fighter Class Aircraft (전투기급 항공기 기동성 증대를 위한 카나드-앞전플랩 스케줄링)

  • Chung, In-Jae;Kim, Sang-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.2
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    • pp.165-170
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    • 2007
  • During the conceptual design phase of a wing-body-canard type fighter class aircraft, as a method of maneuverability enhancement for an aircraft, effects of canard-leading edge flap scheduling have been studied. In this study, corrected supersonic panel method has been used to predict the drag polar characteristics due to canard-leading edge flap deflections in the high speed regime. Utilizing the predicted drag polar curves, the canard-leading edge flap scheduling laws have been established. These scheduling laws are the relation of canard-leading edge flap deflections and the flight conditions to maximize the lift-drag ratio. Based on the results obtained from the canard-leading edge flap scheduling, the present method has shown to be useful to enhance the maneuverability of wing-body-canard type fighter class aircraft.

COMPARISON OF TURBULENCE MODELS ON ANALYSIS OF AIRCRAFT CONFIGURATIONS AT TRANSONIC SPEED (천음속 영역에서 항공기 유동해석에 미치는 난류모델의 영향 비교)

  • Huh, J.;Lee, N.;Lee, S.;Kwak, E.
    • Journal of computational fluids engineering
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    • v.20 no.1
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    • pp.47-56
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    • 2015
  • In this paper, we study the effect of various turbulence models by comparing the aerodynamic characteristics and the flow patterns computed for aircraft models. An in-house CFD solver, MSAPv, that solves the three dimensional RANS equations with the turbulence model equations is used. The turbulence models used in this study are the Spalart-Allmaras model, Menter's $k-{\omega}$ SST model, Coakley's $q-{\omega}$ model, and Huang and Coakley's $k-{\varepsilon}$ model. DLR-F6 WB and WBNP configurations are selected for the study. We concentrate on the separated flow pattern variations with the turbulence models at the wing-body junction and the wing-pylon junction as well as drag polar curves.

Hydrodynamic characteristics of cambered NACA0012 for flexible-wing application of a flapping-type tidal stream energy harvesting system

  • Sitorus, Patar Ebenezer;Park, JineSoon;Ko, Jin Hwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.225-232
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    • 2019
  • In recent years, nonlinear dynamic models have been developed for flapping-type energy harvesting systems with a rigid wing, but not for those with a flexible wing. Thus, in this study, flexible wing designs of NACA0012 section are proposed and measurements of the forces of rigid cambered wings, which are used to estimate the performance of the designed wings, are conducted. Polar curves from the measured lift and drag coefficients show that JavaFoil estimation is much closer to the measured values than Eppler over the entire given range of angles of attack. As the camber of the rigid cambered wings is increased, both the lift and drag coefficients increase, in turn increasing the resultant forces. Moreover, the maximum resultant forces for all rigid cambered wings are achieved at the same angle of attack as the maximum lift coefficient, meaning that the lift coefficient is dominant in representations of the wing characteristics.