비정상 Source-Doublet 패널 기법을 이용한 헬리콥터 로터 공력 해석

국문 초록 (Abstract)

본 연구의 목적은 여러 가지 비행 모드 상의 로터 성능을 효율적으로 예측하는 것이다. 헬리콥터의 공력 특성을 예측하기 위한 비정상 source-doublet 패널 기법 기반의 수치 기 법을 개발하였다. 후류의 형상 예측에는 시간 전진 자유후류모델이 사용되었다. 점성에 의한 확산을 고려한 후류의 roll-up 모사를 위하여 후류의 doublet 패널은 같은 강도의 와류고리로 대체하여 계산하였다. 후류와 양력면의 충돌 문제는 표면격자 내부에 들어간 와류고리의 포텐셜값을 제거하여 해결하였다. 제자리비행의 해석 시에 나타나는 와류 불안정성의 해결에는 slow starting과 vortex core growth 모델을 사용하였다. 로터 공력 해석 프로그램은 제자리비행과 전진비행에 대한 실험 결과와 비교하여 검증하였으며, 실험치와 일치하는 결과를 얻을 수 있었다.

다국어 초록 (Multilingual Abstract)

The purpose of this study is an efficient estimation of the time-dependent performance of rotors at various flight modes. A numerical technique based on the unsteady source-doublet panel method is developed to predict aerodynamic characteristics of helicopter rotor flowfields. A time-marching free wake model is used for wake consideration. For wake roll-up simulation in consideration of viscous diffusion, the wake doublet panel with constant strength is replaced by equivalent vortex ring. The potential value of the wake vortex ring inside the solid boundary was removed to deal with the wake-body collision problem. The vortex instability of hovering mode is settled by slow starting and a vortex core growth model. The rotor aerodynamic analysis program is validated by the experimental data of a helicopter rotor in hover and forward flight. The computed results show good agreement with the experimental data.

목차 (Table of Contents)

• ABSTRACT
• 초록
• Ⅰ. 서론
• Ⅱ. 지배방정식 및 수치해석기법
• Ⅲ. 와류 불안정성
• Ⅳ. 해석 결과
• Ⅴ. 결론
• 후기
• 참고문헌

참고문헌 (Reference)

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