• 한국항공우주학회지
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• 제45권6호
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• pp.455-462
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• 2017

지금까지, 고속 비행과 수직이착륙의 장점을 갖는 비행체에 대한 많은 연구가 있었다. 최근 대중화된 멀티콥터 형태의 드론은 수직이착륙과 다루기가 쉬운 장점을 가지나, 수십 Km 이상의 장거리 임무에는 적합하지 않다. 이에, 본 연구에서는 다수의 프로펠러를 고정익에 결합한 복합형 시제기를 설계 및 제작하였다. 복합형 시제기는 멀티콥터와 고정익의 단순한 결합이 아닌, 멀티콥터의 다수 프로펠러가 자세제어를 수행하여 고정익의 조종면을 대신할 수 있도록 설계하고 비행시험을 통해 자세제어 성능을 확인하였다. 복합형 시제기의 자세제어 성능을 유사급 고정익 비행체와 비교한 결과 다수 프로펠러 기반 자세제어의 성능이 고정익 비행체의 자세제어 성능과 유사한 성능을 보였다.

• 한국항공운항학회지
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• 제28권3호
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• pp.12-17
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• 2020

Avionics is a compound word of aviation and electronics that began to be used in the late 1930s. In the components or sub-systems installed to the aircraft, avionics is something that works by electronic technology. In the past, the aircraft mate, the flight engineer, and the radar operators performed the work on board the aircraft but the modern aircraft have replaced these tasks with avionics. the aircraft mechanics who maintain and manage such complex aircraft must have expertise and technics with the development of avionics to maintain aircraft airworthiness. This paper is about the introduction of domestic avionics qualification system and the development of avionics maintenance technology. For this, the SWOT analysis is performed by identifying the internal and external environment. And recommend the strategy and direction of domestic avionics qualification and education system.

• 한국항행학회논문지
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• 제25권1호
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• pp.17-28
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• 2021

최근 많은 나라 대도시의 교통체증과 더불어 지구온난화로 인해 차세대 친환경 교통수단인 eVTOL이 각광받고 있다. 본 연구에서는 많은 유형의 eVTOL 중 고정로터와 틸트로터가 결합된 복합형 eVTOL인 현대자동차 S-A1의 외부형상을 벤치마킹하여 역설계 기법을 활용하여 기본 형상을 구현하였다. CATIA를 사용하여 기본 형상을 구현한 후 항공기 설계 및 공력해석 프로그램인 OpenVSP, XFLR5를 사용하여 공력해석을 수행하였고 비교분석을 통해 익형과 붙임각, 상/하반각을 선택한 후 항공기 표면적 및 항력, 양력을 계산하였다. 또한 주어진 임무형상을 수행하기 위한 필요 동력을 산정하고 추정식과 자료조사를 통하여 구성품과 전체 무게를 추정하였다.

• 항공우주기술
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• 제12권2호
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• pp.221-229
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• 2013

인간동력항공기의 개념을 분석하여 최고 성능의 인간동력항공기 개발을 위하여 필요시되는 동력증강 및 항력감소 설계에 대하여 연구하였다. 2012년 인간동력항공기 시범경진대회에 출전하기 위하여 유선형 동체 채택에 의한 항력저감 및 팔과 다리 힘 동시사용에 의한 동력증강개념을 제시하였으며 개념 확인을 위하여 동체의 전산해석 및 동력장치 설계를 수행하였다. 유선형 동체의 효과를 최대한 이용하기 위해서는 동체형상 설계가 중요하며 팔의 동력을 이용하기 위해서는 조종 장치의 설계가 중요하고 비행실험이 요구된다.

• 항공우주시스템공학회지
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• 제2권3호
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• pp.1-6
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• 2008

The tilt rotor aircraft has the flight characteristics which takes off vertically like a helicopter and flies forward like an airplane. Especially, the transition process from a helicopter to an airplane mode requires not only the mixing of control inputs but also the stability and controllability augmentation system(SCAS) in order to keep the safe flight because there are compound flight dynamic characteristics of a helicopter and an airplane including non-linearity, uncertainty. This paper describes the design of SCAS in a lateral motion for the tilt rotor aircraft based on the $H_{\infty}$ control method, which was performed from mathematical model with weighting matrix based on the relationship between the $H_{\infty}$ norm and the sensitivity function. Through simulation analysis for the controller designed on the $H_{\infty}$ control theory, it was shown that this method may be applied to the control design of the tilt rotor aircraft.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.501-506
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• 2005

With the respective collapse characteristics of aluminum and CFRP (Carbon Fiber Reinforced Plastics) tubes in mind, axial collapse tests were performed for aluminum/CFRP compound tubes, which are composed of square or circular shaped aluminum tubes wrapped with CFRP outside. In this study, the collapse modes and the energy absorption characteristics were analyzed for aluminum/CFRP compound tubes which have different fiber orientation angle of CFRP. Fracture modes in the aluminum/CFRP compound tubes were rather stable than those in the CFRP tubes alone, probably due to the ductile nature of the inner aluminum tubes. The absorbed energy per unit volume of the aluminum or the aluminum/CFRP compound tubes was higher than that of CFRP tubes. Meanwhile, the absorbed energy per unit mass, for the light-weight design aspect was higher in the aluminum/CFRP compound tubes than in the aluminum tubes or the CFRP tubes. The energy absorption turned out to be higher in circular tubes than in square tubes. Beside the collapse modes and the energy absorption characteristics were influenced by the orientation angle, and the compound tubes took the most effective energy absorption when the fiber orientation angle of CFRP was 90 degrees.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.641-650
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• 2017

In order to include the design capability for a compound rotorcraft in a helicopter conceptual design and optimization framework, relevant further improvement was planned and conducted. Previously, a certain conceptual design optimization framework was developed by the present authors to design a modern rotorcraft with single main and tail rotor. The previously developed framework was further improved to expand its capability for a compound rotorcraft. Specifically, its power estimation algorithm was upgraded by using a comprehensive rotorcraft analysis program, CAMRAD II. The presently improved conceptual design and optimization framework was validated using data of the XH-59A aircraft.

• 한국항공운항학회지
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• 제22권3호
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• pp.60-67
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• 2014

Technical history of VTOL aircraft is examined from the early helicopter appearance to recent experimental rotorcraft in order to distinguish the core issues of those aircraft. Performance and technological challenges of some VTOL aircraft such as tilt rotor, convertiplane, gyroplane, and coaxial helicopter are discussed. As a new generation high performance rotorcraft, Sikorsky X2 is intensively investigated. Considering the developmental history of X2, the autorotational ability at high speed is recognized as a core technology. Analytic method of autorotation and some results are shown and presents research subjects related to the future Korean high performance rotorcraft.

• 한국산업보건학회지
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• 제30권2호
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• pp.174-184
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• 2020

Objectives: The purpose of this study was to improve the working environment by identifying the work satisfaction of the cleaning workers of the aircraft and measuring and assessing the harmful factors of the cleaning process. Methods: We asked 23 cleaning companies for questionnaires and got 100 answers from 5 companies. The A-E Airline health manager has been contacted to establish a site survey schedule. The in-flight and lounge were measured using direct reading equipment. The harmful factor to be measured are noise, dust, temperature, volatile organic compound, total airborne bacteria, and total airborne bacteria. Results: Uncomfortable positions when replacing blanket, cleaning the table, and cleaning the floor have been identified as factor that reduce work satisfaction. Noise when replacing newspapers and cleaning toilets has been identified as a factor that lowers work satisfaction. Temperature and humidity were found to reduce work satisfaction during in-flight disinfection. Measurements of aircraft cabin and lounge with direct read equipment have shown that none of the items exceed the exposure criteria. Conclusions: As a result of measuring direct-reading equipment, no items exceeded the exposure criteria for each harmful factor. A clear survey of the working environment is required based on the results, and additional research is needed using personal sample measurement.

• 한국항공우주학회지
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• 제40권1호
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• pp.12-22
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• 2012

샤프트각이 감소하며 비행 속도가 증가하는 자동회전 상태의 로터에 대한 성능 변화를 해석하였다. BO-105 헬리콥터의 로터에 비틀림이 없는 NACA 0012 단면을 가지는 깃을 해석하였고 변수에 대한 자동회전의 영역을 구하기 위해 과도모사법(TSM)이 사용되었다. 고속 비행에서 압축성 효과를 모사하기 위해 압축성 Navier-Stokes 솔버로 해석된 2차원 공력 데이터가 사용되었으며 유도 속도장을 모사하기 위해 Pitt/Peters의 유도속도 이론이 사용되었다. TSM으로 구해진 정상 자동회전 상태에 대하여 추력계수와 양력계수, 양항비를 계산하였으며 로터의 양력과 동력을 구하여 BO-105 헬리콥터와 비교하였다. 복합 항공기의 개념을 도입할 때 자동회전하는 로터와 날개의 양력 및 동력 분담률을 고찰하였다.