• 제목/요약/키워드: Hover

검색결과 126건 처리시간 0.033초

날개짓 비행체의 양력 변위 (Lift Force Variation of Flapping Wing)

  • 홍영선
    • 한국군사과학기술학회지
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    • 제10권1호
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    • pp.33-43
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    • 2007
  • Using the more common conventional chordwise aerodynamic approach, flapping a flat plate wing with zero degree chordwise pitch angle of attack and no relative wind should not produce lift. However, in hover, with no forward relative velocity and zero degree chordwise pitch angle of attack, flapping flat plate wings does in fact produce lift. In the experiments peformed for this paper, the flapping motion is considered pure(downstroke and upstroke) with no flapping stroke plane inclination angle. No changes in chordwise pitch angle are made. The total force is measured using a force transducer and the net aerodynamic force is determined from this measured total force by subtracting the experimentally determined inertial contribution. These experiments were repeated at various flapping frequencies and for various wing planform sizes for flat plate wings. The trends in the aerodynamic lift variation found using a force transducer have nearly identical shape for various flapping frequencies and wing planform sizes.

The MPI CyberMotion Simulator: A Novel Research Platform to Investigate Human Control Behavior

  • Nieuwenhuizen, Frank M.;Bulthoff, Heinrich H.
    • Journal of Computing Science and Engineering
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    • 제7권2호
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    • pp.122-131
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    • 2013
  • The MPI CyberMotion Simulator provides a unique motion platform, as it features an anthropomorphic robot with a large workspace, combined with an actuated cabin and a linear track for lateral movement. This paper introduces the simulator as a tool for studying human perception, and compares its characteristics to conventional Stewart platforms. Furthermore, an experimental evaluation is presented in which multimodal human control behavior is studied by identifying the visual and vestibular responses of participants in a roll-lateral helicopter hover task. The results show that the simulator motion allows participants to increase tracking performance by changing their control strategy, shifting from reliance on visual error perception to reliance on simulator motion cues. The MPI CyberMotion Simulator has proven to be a state-of-the-art motion simulator for psychophysical research to study humans with various experimental paradigms, ranging from passive perception experiments to active control tasks, such as driving a car or flying a helicopter.

대각 내재적 조화균형법을 이용한 헬리콥터 로터 블레이드의 비정상 공력 해석 (UNSTEADY AERODYNAMIC ANALYSIS OF HELICOPTER ROTOR BLADES USING DIAGONAL IMPLICIT HARMONIC BALANCE METHOD)

  • 임동균;최성임;박수형;권장혁
    • 한국전산유체공학회지
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    • 제16권4호
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    • pp.21-27
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    • 2011
  • In this paper, the diagonal implicit harmonic balance method is applied to analyze helicopter rotor blade flow. The periodic boundary condition for Fourier coefficients is also applied in hover and forward flight conditions. It is available enough to simulate the forward flight problem with only one rotor blade using the periodic boundary condition in the frequency domain. In order to demonstrate the present method, Caradonna & Tung's rotor blades were used and the results were compared to the time-accurate method and experimental data.

주변 구조물을 포함하는 훨타워 로터 블레이드 공력 해석 (A NUMERICAL INVESTIGATION OF THE EFFECT OF SURROUNDING BUILDINGS ON THE AERODYNAMIC PERFORMANCE OF A ROTOR SYSTEM ON THE WHIRL TOWER)

  • 강희정
    • 한국전산유체공학회지
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    • 제17권2호
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    • pp.78-84
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    • 2012
  • Numerical calculations were performed to investigate the influence in aerodynamic characteristics of a rotor system by surrounding structures and the ground effect for the rotor blade on a whirl tower is also investigated. Three dimensional Navier-Stokes simulations were carried out by using unstructured overset mesh technique and parallel computation. The calculated hover performance showed good agreement with the experimental result and showed that the structures around the whirl tower did not affect the aerodynamic characteristics of the blade. The ground effect was studied by comparing with the numerical result for the out of ground condition and the result of an analytic model.

파라메타 각 변화를 고려한 힌지없는 헬리콥터 로우터의 공력탄성학적 안정성 (The Study on the Aeroelastic Stability of Hingeless Helicopter Rotor in Hover Considering Parametric Angle Changes)

  • 한창헌;김승조
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.386-391
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    • 1998
  • The effect of the changes in parameter angles(precone, droop, sweep) on the lead-lag damping was focused on. Experiment was made with hingeless 4-blade rotors and NACA 0012 airfoil. For the measurement of the rotating natural frequencies and lead-lag damping, non-rotating swash plate was oscillated at the regressing lag mode frequency and the data were acquired after the excitation was cut off. Analysis was made using a finite element formulation based on Hamilton's principle. The main blade is assumed as elastic beams. Quasi-steady strip theory is used to obtain aerodynamic forces, and non-circulatory forces are also included.

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반작용 구동로터 시스템의 사이징 방법론에 대한 고찰 (Review of Reaction Drive Rotor System Sizing Methodology)

  • Ali, Freshipali Rasheeth;Jeon, Kwon-Su;Lee, Jae-Woo
    • 한국항공운항학회:학술대회논문집
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    • 한국항공운항학회 2016년도 춘계학술대회
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    • pp.9-13
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    • 2016
  • Reaction drive rotor system is capable of providing hover and low speed capabilities to different aircraft concepts such as stopped rotor wing, canard rotor wing, compound gyroplane etc. Existing sizing and analysis tools for shaft drive rotor system cannot be applied directly to this system. The available methodologies to size this system were reviewed. Power available calculation procedure and factors affects it were addressed prior to sizing process. Various design issues of this system due to interrelationship of internal gas flow dynamics and rotor external aerodynamics was discussed. Finally, a modification that is required in existing sizing methodologies was identified and combined approach in sizing process to consider the interrelationship among engine, rotor and blade duct was introduced.

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An Experimental Study on Lift Force Generation Resulting from Spanwise Flow in Flapping Wings

  • Hong, Young-Sun
    • International Journal of Aeronautical and Space Sciences
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    • 제7권2호
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    • pp.86-103
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    • 2006
  • Using a combination of force transducer measurement to quantify net lift force, high frame rate camera to quantify and subtract inertial contributions, and Digital Particle Image Velocimetry (DPIV) to calculate aerodynamic contributions in the spanwise plane, the contribution of spanwise flow to the generation of lift force in wings undergoing a pure flapping motion in hover is shown as a function of flapping angle throughout the flapping cycle. These experiments were repeated at various flapping frequencies and for various wing planform sizes for flat plate and span wise cambered wings. Despite the previous identification of the importance of span wise fluid structures in the generation of lift force in flapping wings throughout the existing body of literature, the direct contribution of spanwise flow to lift force generated has not previously been quantified. Therefore, in the same manner as commonly applied to investigate the chordwise lift distribution across an airfoil in flapping wings, spanwise flow due to bulk flow and rotational fluid dynamic mechanisms will be investigated to validate the existence of a direct component of the lift force originating from the flapping motion in the spanwise plane instead.

SRFIMF를 이용한 멀티팬 부상기의 YAW제어에 관한 연구 (A Study on Yaw Control of Multi-Fan Hovering with SRFIMF)

  • 박선국;최부귀
    • 한국통신학회논문지
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    • 제17권4호
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    • pp.361-370
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    • 1992
  • 수직 이착륙기와 같은 비행체의 정지비행 도중 비행체의 위치각, 각속도, 각가속도와 같은 상태량을 궤환 시킨 SRFIMF(State Rate Feedback Implicit Model-Following)이론을 이용하여 4개의 팬을 갖는 부상제어시스템을 구성하였다. 이 부상제어시스템의 yaw제어를 행하여, 각 상태궤환이득 및 전향경로 이득을 변화시켜 부상제어시스템의 특정을 해석하였으며, 부상시스템과 같은 제어계에 SRFIMF방식을 적용시켜 그 타당성을 조사하였다.

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OCID 알고리듬을 이용한 헬리콥터 시스템 판별 (System Identification of Helicopter Using OCID Algorithm)

  • 박문수;김병두;노치원;홍석교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 B
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    • pp.556-559
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    • 1999
  • In this paper, the Observer Controller IDentification/Eigensystem Realization Algorithm(OCID/ERA) is applied to identify the state space model of a helicopter in hover from a given set of the general input-output data. The objective of this paper is the evaluation of the utility of the OCID/ERA approach to the system identification of a system which has natural unstable mode like a helicopter and to give some guidelines before applying the technique to the real system. As it mentioned above, since a model helicopter is unstable naturally, the closed-loop system identification method(OCID/ERA) using excitation, output and feedback signals of the simulated system is applied.

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모형헬리콥터의 수학적 해석 (Mathematical Analysis of Model Helicopter)

  • 김양욱;이광원;이자성;홍석교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 B
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    • pp.818-821
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    • 1999
  • Helicopter system is regarded as a challenging example in multivariable robust control application since the dynamics of helicopter is highly coupled and nonlinear. In this paper, Dynamic equations for model helicopter at hover are derived. Various system properties are stated with respect to control of the attitude of the vehicle. A linearized model is used to analyse the system stability and to design the attitude controller. The simulation results of LQG controller are presented.

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