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이정훈(Jung-Hoon Lee),최병철(Byung-Chul Choi) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.4
본 연구는 경비행기인 창공-91의 인증 획득을 위한 비행시험의 일부로서 상승성능을 파악하기 위하여 수행되었다. 창공-91은 1993년에 대한민국의 건설교통부로부터 최초로 인증을 취득한 단발엔진을 장착한 일반유형의 5인승 항공기이다. 상승을 위한 비행시험 절차 및 자료는 형식증명을 획득하는데 사용되었다. 톱니형 상승 데이터로부터 양항곡선 방법으로 데이터를 처리하여 창공-91의 최대상승률, 최대상승각 속도, 최대상승률 속도, 그리고 절대상승한도를 구하였다. 또한, 상승성능의 결과로부터 양항곡선식을 구함으로써 형상항력계수와 오스왈드 효율계수를 비행기 설계시의 값과 비교하였다. This study is performed to find out the climb performance of light airplane, Chang Gong-91, as a part of flight test to acquire the certification. Chang Gong-91 is a 5-passenger light aircraft of normal category with single reciprocating engine, and the first officially certified by Korean Ministry of Construction and Transportation in 1993. These flight test procedure and data for climb performance are used to get type certification. We have got maximum climb rate for operating altitude, best angle of climb speed, best rate of climb speed, and absolute ceiling of Chang Gong-91 using drag polar data reduction method from sawtooth climb flight data. Also we compare the form drag coefficient from the results of climb performance and Oswald's effectiveness coefficient to design values using lift-drag curve of light airplane.
제자리, 상승 및 하강 비행하는 이중 덕티드 팬 비행체의 공력 특성에 대한 수치적 연구
이유진,이재동,정형석,정혜승,임진우,박동훈 한국전산유체공학회 2023 한국전산유체공학회지 Vol.28 No.3
Numerical analysis is conducted for a dual-ducted fan aircraft at hover, climb, and descent flight conditions to investigate the aerodynamics and stability characteristics. For practical and rapid analysis, the virtual disk method is employed and, a comparison with the results obtained from the sliding mesh method is performed to evaluate the validity of the method. During hovering flight, an imbalance in pitching moment arises at high collective pitch angles of the ducted-fans, which can deteriorates longitudinal stability. For climb flight condition, pitching moment increases and normal force decreases with climb velocity. Rolling and yawing moment exhibit minor changes at low collective pitch angles but significant changes occur at high pitch angles. For descent flight, thrust increases and pitching moment remains small as descent velocity increases. However, a considerable decrease in pitching moment with descent velocity is identified when the collective pitch angles are low.