• 제목/요약/키워드: Hover

검색결과 126건 처리시간 0.032초

축소형 틸트로터 무인기의 안전줄 호버 시험 (Tethered Hover Test for Small Scaled Tilt-rotor UAV)

  • 박범진;유창선;장성호;최성욱;구삼옥;강영신
    • 한국항공운항학회지
    • /
    • 제15권4호
    • /
    • pp.9-16
    • /
    • 2007
  • Tilt rotor aircraft can take off and land vertically and cruise faster than any other helicopter. A scaled flight demonstration model of a tilt rotor aircraft has been developed by KARI. Because the flight characteristics of tilt rotor are not well known, the developed scaled model would be helpful to evaluate flight control algorithm of a full scale aircraft. The tethered hover test has been performed in order to improve hover flight characteristics of tilt rotor aircraft prior to flight test of the small scaled model. During the tethered hover test, the performance of rotor speed governor, rate SAS (Stability Augmentation System) and control surface mixers have been evaluated. We expect that the results of real flight hover test would be quite same as tethered hover test. Therefore the tethered hover test results will reduce the risk of flight test properly by fixing some of hidden problems which might occur during the flight test. This paper presents the results of tethered hover test in detail and shows how it could be final ground test before flight test. The control mixer gain and rate SAS feedback gains were modified in order to get higher controllability and stability during the tethered hover flight. The rotor governor showed that it could keep rotor RPM constant with very small deviation even during severe pilot collective input change. The tethered hover test results gave pilot and engineers confirmation and experience about the scheduled flight test.

  • PDF

한국형 기동헬기 블레이드의 제자리 비행 공력 해석 (Aerodynamic Calculations in Hover of KUH Rotor Blade)

  • 강희정;김승호;정문승;이희동;권오준
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2008년도 춘계학술대회논문집
    • /
    • pp.25-28
    • /
    • 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.

  • PDF

Assessment of Rotor Hover Performance Using a Node-based Flow Solver

  • Jung, Mun-Seung;Kwon, Oh-Joon;Kang, Hee-Jung
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제8권2호
    • /
    • pp.44-53
    • /
    • 2007
  • A three-dimensional viscous flow solver has been developed for the prediction of the aerodynamic performance of hovering helicopter rotor blades using unstructured hybrid meshes. The flow solver utilized 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. Calculations were performed at three operating conditions with varying tip Mach number and collective pitch setting for the Caradonna-Tung rotor in hover. Additional computations are made for the UH-60A rotor in hover. Reasonable agreements were obtained between the present results and the experiment in both blade loading and overall rotor performance. It was demonstrated that the present vertex-centered flow solver is an efficient and accurate tool for the assessment of rotor performance in hover.

수면호버링 드론을 이용한 흑산도 해저지형 탐사 기법 연구 (Study on Exploration Method of Seabed Around Heuksando Using Hover Drones)

  • 김형균;이영숙
    • 한국멀티미디어학회논문지
    • /
    • 제23권1호
    • /
    • pp.102-110
    • /
    • 2020
  • This study covers exploration of seabed around Heuksando Island using hover drones. To do so, we inspected the terrain of the island and set autonomous flight waypoints on each area of the island's shores. Next, we designated seabed scan radius for drones. Then the drones fitted with laser sensor hover autonomously on their assigned area and acquire seabed data. Finally, we match the seabed data on all areas according to GPS. Our final goal is to make immersive VR maritime cultural map based on 『Jasan Urbo』.

3 자유도 비행체 시스템의 이벤트 트리거 기반의 H2 자세 제어기 설계 (Event-Triggered H2 Attitude Controller Design for 3 DOF Hover Systems)

  • 정혜인;한승용;이상문
    • 대한임베디드공학회논문지
    • /
    • 제15권3호
    • /
    • pp.139-148
    • /
    • 2020
  • This paper is concerned with the H2 attitude controller design for 3 degree of freedom (DOF) Hover systems with an event-triggered mechanism. The 3 DOF Hover system is an embedded platform for unmanned aerial vehicle (UAV) provided by Quanser. The mathematical model of this system is obtained by a linearization around operating points and it is represented as a linear parameter-varying (LPV) model. To save communication network resources, the event-triggered mechanism (ETM) is considered and the performance of the system is guaranteed by the H2 controller. The stabilization condition is obtained by using Lyapunov-Krasovskii functionals (LKFs) and some useful lemmas. The effectiveness of the proposed method is shown by simulation and experimental results.

소형 로터 블레이드의 제자리 비행 성능 시험장치 개발 및 검증 (Development and Verification of Small-Scale Rotor Hover Performance Test-stand)

  • 이병언;서진우;변영섭;김정;이관중;강범수
    • 한국항공우주학회지
    • /
    • 제37권10호
    • /
    • pp.975-983
    • /
    • 2009
  • 본 논문은 동축반전 로터 블레이드의 성능 특성 파악을 위한 선행연구로서, 단일 로터 블레이드에 대한 공력 데이터 획득 및 성능 특성을 확인하기 위한 연구에 중점을 두었다. 이를 위해 제자리 비행 상태에서 추력과 토크의 측정이 가능한 소형 로터 블레이드용 회전 시험장치를 구성하고 제작하였다. 로터 회전 시험장치는 회전장치부, 센서부, 그리고 데이터 획득 시스템으로 구성되었으며, 고정된 회전속도에서 콜렉티브 피치각을 변화시키면서 추력과 토크를 측정할 수 있도록 하였다. 이를 통하여 저 레이놀즈 수 ($Re{\approx}3{\times}10^5$) 영역에서 운용되는 단일 로터의 제자리 비행 성능 시험을 수행하였고 소형 로터 블레이드의 제자리 비행 성능을 획득하여 로터 회전 시험장치의 성능을 검증하였다.

정지 비행하는 로터 블레이드의 전산 유체-구조 결합 해석 (Computational analysis of coupled fluid-structure for a rotor blade in hover)

  • 김해동
    • 한국항공우주학회지
    • /
    • 제36권12호
    • /
    • pp.1139-1145
    • /
    • 2008
  • 로터 블레이드의 구조변형을 포함한, 제자리 비행하는 로터 블레이드의 공력해석을 수행하였다. 와류포획능력을 향상시킨 전산유체 코드와 간단한 오일러-베르누이 보 모델에 기반을 둔 구조역학 방정식을 결합시켜 회전익 유동에 대한 연계 계산을 수행하였으며 계산결과 타당한 로터블레이드 구조변형 및 공력특성을 얻었다.

Multi-Point Aerodynamic Shape Optimization of Rotor Blades Using Unstructured Meshes

  • Lee, Sang-Wook;Kwon, Oh-Joon
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제8권1호
    • /
    • pp.66-78
    • /
    • 2007
  • A multi-point aerodynamic shape optimization technique has been developed for helicopter rotor blades in hover based on a continuous adjoint method on unstructured meshes. The Euler flow solver and the continuous adjoint sensitivity analysis were formulated on the rotating frame of reference. The 'objective function and the sensitivity were obtained as a weighted sum of the values at each design point. The blade section contour was modified by using the Hicks-Henne shape functions. The mesh movement due to the blade geometry change was achieved by using a spring analogy. In order to handle the repeated evaluation of the design cycle efficiently, the flow and adjoint solvers were parallelized based on a domain decomposition strategy. A solution-adaptive mesh refinement technique was adopted for the accurate capturing of the wake. Applications were made to the aerodynamic shape optimization of the Caradonna-Tung rotor blades and the UH-60 rotor blades in hover.

실험을 통한 소형 무인헬리콥터의 공력인자 도출 및 제자리 비행 성능 예측 (Prediction of Hover Performance on Development of Small-Scale UAV using Numerical and Experimental Approach)

  • 이병언;;변영섭;송준범;강범수
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2008년도 추계학술대회B
    • /
    • pp.2548-2553
    • /
    • 2008
  • Prediction of the rotor blade performance is important for determining design factors such as weight and size in development of a small-scale helicopter. Generally, prediction of helicopter performance means the estimation of the power required for a given flight condition. However, due to lack of test data and analyzed results for small-scale rotor blade operated at low Reynolds numbers ($Re{\approx}10^5$), this is not an easy task. As an initial research, this work performs a modeling of a single rotor configuration with FLIGHTLAB and a experimental research with rotor test bed. In this process, we performed small-scale isolated single rotor by experimental and numerical method and achieved good agreement of the hover performance on the test data and simulation results.

  • PDF

Performance predictions and acoustic analysis of the HVAB rotor in hover

  • Mali, Hajar;Benmansour, Kawtar;Elsayed, Omer;Qaissi, Khaoula
    • Advances in aircraft and spacecraft science
    • /
    • 제9권4호
    • /
    • pp.319-333
    • /
    • 2022
  • This work presents a numerical investigation of the aerodynamics and aero acoustics of the HVAB rotor in hover conditions. Two fully turbulent models are employed, the one-equation Spalart-Allmaras model and the two-equation k-ω SST model. Transition effects are investigated as well using the Langtry-Menter γ-Re θt transition transport model. The noise generation and propagation are being investigated using the Ffows-Williams Hawking model for far-field noise and the broadband model for near-field noise. Comparisons with other numerical solvers and with the PSP rotor test data are presented. The results are presented in terms of thrust and power coefficients, the figure of merit, surface pressure distribution, and Sound pressure level. Velocity, pressure, and vortex structures generated by the rotor are also shown in this work. In addition, this work investigates the contribution of different blade regions to the overall noise levels and emphasizes the importance of considering specific areas for future improvements.