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강제진동 기법을 이용한 무미익 비행체의 동안정 미계수 측정

Measurement of Dynamic Stability Derivatives of Tailless Lamda-shape UAV using Forced Oscillation Method

  • Yang, Kwangjin (Department of Aerospace/Mechanical Engineering, Korea Air Force Academy) ;
  • Chung, Hyoungseog (Department of Aerospace/Mechanical Engineering, Korea Air Force Academy) ;
  • Cho, Donghyun (Department of Aerospace/Mechanical Engineering, Korea Air Force Academy) ;
  • An, Eunhye (Department of Aerospace/Mechanical Engineering, Korea Air Force Academy) ;
  • Ko, Joonsoo (School of Aerospace & Mechanical Engineering, Korea Aerospace University) ;
  • Hong, JinSung (The 7th Research and Development Institute, Agency for Defense Development) ;
  • Kim, Yongduk (The 7th Research and Development Institute, Agency for Defense Development) ;
  • Lee, MyungSup (The 7th Research and Development Institute, Agency for Defense Development) ;
  • Hur, Gi-Bong (The 7th Research and Development Institute, Agency for Defense Development)
  • 투고 : 2016.04.12
  • 심사 : 2016.06.14
  • 발행 : 2016.07.01

초록

본 연구에서는 강제진동 기법을 이용하여 람다형상을 갖는 무미익 무인기의 동안정 미계수를 측정하였다. 강제진동 기법은 시험모델을 일정한 크기의 각 변위로 진동시키면서 항공기에 작용하는 공력의 시간이력(time history) 데이터를 측정하고, 입력진동 대비 공력데이터의 위상차와 진폭을 추출함으로써 비행체의 동안정 미계수를 계산하는 방법이다. 본 연구에서는 롤, 피치, 요 방향으로 각각 진동시킬 수 있는 실험 장치를 설계, 제작하여 국내 최초로 무미익 항공기의 동안정 미계수 측정 시험을 수행하였다. 롤 댐핑 동안정 미계수 측정 결과, 진동 주파수와 진동의 크기가 증가하여도 동안정 미계수의 경향성은 동일하게 나타나며, 전반적으로 측정 받음각 구간에서 안정한 특성을 보였다. 피치 댐핑 동안정 미계수의 경우 작은 진동 주파수에서 동적으로 더 안정해지며, 받음각 $15^{\circ}$ 이상에서는 동적으로 불안정해지는 경향성을 보였다. 각 시험데이터들은 반복성 시험을 통해 데이터의 신뢰성을 검증하였으며, 본 연구에 적용된 강제진동 기법이 무미익 항공기의 동안정 미계수를 성공적으로 측정할 수 있음을 확인하였다.

In this experimental study, the dynamic stability derivatives of a tailless lambda-shape UAV are estimated from time history data of aerodynamic moments measured from the internal balance while the test model is forced to oscillate at given frequencies and amplitudes. A 3-axis forced oscillation apparatus is designed to induce decoupled roll, yaw, pitch oscillations respectively. The results show that the roll damping derivatives remain stable at the entire range of angle of attack tested, whereas the pitch damping derivatives become unstable beyond $15^{\circ}$ angle of attack. The amplitude and frequency have little impact on roll damping derivatives while the smaller amplitude and frequency of oscillation improves the pitch stability. The yaw damping derivative values are fairly small as expected for a tailless configuration. The results indicate that the proposed methodology and test apparatus area valid for estimating the dynamic stability derivatives of a tailless UAV.

키워드

참고문헌

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