• 한국항공운항학회지
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• 제24권2호
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• pp.19-24
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• 2016

Positional stability analysis based on aerodynamic forces and induced moments of formation flight using two small aircraft models is presented. The aerodynamic force and moments of the trailing aircraft are analyzed in the aspect of flight stability. The induced moments with the change of local flow direction by wing-tip vortex from the leading aircraft can affect the flight positional stability of aircraft in closed formation flight. Aerodynamic forces and moments of trailing aircraft model are measured by 6-component internal balance at the 49 locations with vertical and lateral space between two aircraft models. Results are shown that the positional stability of trailing aircraft in formation flight can be analyzed by positional stability derivatives with vertical and lateral space. It is concluded that flying positions can be important factors for aircraft position stability due to induced aerodynamic force and moments with vertical and lateral spacing by the variation of flow pattern from the leading aircraft in formation flight.

• 한국항공우주학회지
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• 제35권2호
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• pp.165-170
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• 2007

날개-동체-카나드 형상 전투기급 항공기 개념설계 기간 동안, 항공기 기동성 증대 방안으로서 카나드-앞전플랩 스케줄링 효과에 대한 연구를 수행하였다. 본 연구에서는 고속 영역에서 카나드-앞전플랩 변위각에 의한 양항특성을 예측하기 위하여 보정된 초음속 패널 방법을 사용하였다. 예측된 양항곡선을 활용하여 카나드-앞전플랩 스케줄링 법칙을 설정하였다. 이러한 카나드-앞전플랩 스케줄 법칙은 양항비를 최대로 하는 카나드-앞전플랩 굽힘과 비행조건과의 관계이다. 카나드-앞전플랩 스케줄링에 의한 결과를 기초로, 제시된 방법은 날개-동체-카나드형상 전투기급 항공기의 기동성을 증대하는데 유용한 것으로 확인되었다.

• 한국항공우주학회지
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• 제35권10호
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• pp.899-904
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• 2007

전투기급 항공기 개념설계 기간 중 항공기 초음속 순항성능에 미치는 앞전플랩 굽힘 효과를 분석하기 위하여 1/20 축척 날개-동체-꼬리 형상 모형을 사용한 고속 풍동시험을 수행하였다. 풍동시험을 위한 적절한 앞전플랩 각도를 선정하기 위하여 보정된 초음속 패널 방법을 사용하여 다양한 앞전플랩 굽힘 각도에 따른 공력특성을 분석하였다. 실험 및 수치해석적 접근 결과 분석을 기초로, 앞전플랩 굽힘 효과는 전투기급 항공기의 초음속 순항 성능 증대에 유용한 것으로 확인되었다.

• International Journal of Aeronautical and Space Sciences
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• 제18권2호
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• pp.215-221
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• 2017

An electromagnetic (EM) wave absorber reduces the possibility of radar detection by minimizing the radar cross section (RCS) of structures. In this study, a radar absorbing structure (RAS) was applied to the leading edge of a blended wing body aircraft to reduce RCS in X-band (8.2~12.4GHz) radar. The RAS was composed of a periodic pattern resistive sheet with conductive lossy material and glass-fiber/epoxy composite as a spacer. The applied RAS is a multifunctional composite structure which has both electromagnetic (EM) wave absorbing ability and load-bearing ability. A two dimensional unit absorber was designed first in a flat-plate shape, and then the fabricated leading edge structure incorporating the above RAS was investigated, using simulated and free-space measured reflection loss data from the flat-plate absorber. The leading edge was implemented on the aircraft, and its RCS was measured with respect to various azimuth angles in both polarizations (VV and HH). The RCS reduction effect of the RAS was evaluated in comparison with a leading edge of carbon fabric reinforced plastics (CFRP). The designed leading edge structure was examined through static structural analysis for various aircraft load cases to check structural integrity in terms of margin of safety. The mechanical and structural characteristics of CFRP, RAS and CFRP with RAM structures were also discussed in terms of their weight.

• 품질경영학회지
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• 제32권3호
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• pp.166-181
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• 2004

The aircraft production quality management system in Korea has been implemented to support the developmental phase of Korean aircraft industries, from overhaul of the aircraft and engines to development of military trainer aircraft. After the deletion of the Mil-Q-9858A standard in 1996, Korean aerospace companies established ISO 9001 and AS 9100 as their basic aerospace quality management system specifications. These quality standards were adopted in the same period of time by other leading international aircraft manufacturing companies. This paper presents a future direction on the improvement of quality management systems for Korean aircraft production company by considering (1) Korean governments strategy for the development of Korean aircraft Production industries, (2) short and long term business plan of Korean aerospace industries, and (3) benchmarking leading international company's quality management systems.

• 한국항공우주학회지
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• 제41권11호
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• pp.849-854
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• 2013

본 연구에서는 편대비행하는 고속 항공기의 날개 끝 와류의 공력 간섭 효과를 연구하기 위해서 풍동실험기법이 적용되었다. 편대비행에서 앞선 항공기의 날개 끝에서 발생하는 와류가 뒤따르는 항공기의 공력 특성에 영향을 미칠 수 있다. 흐름의 간섭 효과는 앞선 항공기와 뒤따르는 항공기의 날개 끝 사이의 거리에 따라서 변화된다. 본 연구의 실험결과 앞선 항공기에서 발생되는 날개 끝 와류는 뒤따르는 항공기의 공력 및 모멘트 계수를 변화시킴을 확인하였다. 특히, 후방 항공기의 양력계수는 수직 및 수평 위치에 따라 y/b=-0.125, z/b=0.0에서 가장 많이 증가되거나 y/b=-0.5, z/b=0.38에서 가장 크게 감소됨을 확인하였으며, 두 항공기로부터 발생된 날개 끝 와류의 간섭 현상이 자세히 관찰되었다.

• 한국항공운항학회지
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• 제14권4호
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• pp.48-59
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• 2006

This Study focused on the process of technology transfer for the aircraft development program by the strategic alliance. Especially, this study showed how the learning firms absorb new technology from the foreign leading company. This case study concludes that teachability, asset specificity, relation capital with partner, information sharing system in organization and knowledge base are key factors for absorbing the new technology from the technology leading partner.

• 유통과학연구
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• 제20권9호
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• pp.39-46
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• 2022

Purpose: At the industrial sites of aviation enterprises there is a significant optimization of the main production processes through the use of advanced digital technologies. The most promising are the latest technologies of industrial Internet of Things, active use of big data and practical application of artificial intelligence in production. Research design, data and methodology:The process of creating a competitive product in the high-tech aviation sector is actively linked to the investment appeal of aircraft and helicopter construction products, which is built on the basis of reducing production and time costs through the creation of an effective digital system. Results: The aviation cluster of Rostec State Corporation is currently being transformed in a significant way. The leading enterprises of the Russian aviation industry are actively mastering cooperation schemes using integrated digital management principles and the widespread introduction of digital products from leading Russian vendors. Conclusions: Following the transition to electronic aircraft design technologies and modern materials in the production of aircraft, UAC continues to improve all production processes through robotization and optimization of technological processes, due to the introduction of aircraft assembly technology in accordance with digital models.

• 한국항공우주학회지
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• 제35권7호
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• pp.655-660
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• 2007

카나드 형상 전투기급 항공기 기동성을 증대시키기 위하여 카나드-앞전플랩 스케줄링 법칙을 수립하였다. 이러한 카나드-앞전플랩 스케줄 법칙은 양항비를 최대로 하는 카나드-앞전플랩 변위각과 비행조건과의 관계이다. 이러한 목적으로 고속 영역에서 카나드-앞전플랩 변위각에 의한 양항특성을 예측하기 위하여 보정된 초음속 패널 방법을 사용하였다. 또한 예측된 스케줄링 법칙을 확인하기 위하여 1/20 시험 모형을 이용한 고속 풍동시험을 수행하였다. 고속 풍동시험 결과와 비교 시 초음속 패널 수치해석적 결과는 잘 일치하였다. 실험 및 수치 해석적 연구 결과를 기초로, 제시된 보정된 초음속 패널 방법은 카나드형상 전투기급 항공기 공력설계를 위한 카나드-앞전플랩 스케줄링 법칙 수립에 유용한 것으로 확인되었다.

• Wind and Structures
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• 제29권4호
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• pp.271-277
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• 2019

This work deals with designing the aircraft wing and simulating the flow behavior on it to determine the aerodynamically efficient wing design. A NACA 4412 airfoil is used to design the base wing model. A wing with a rectangular planform and the one with curved leading edge planform was designed such that their surface areas are the same. Then, a comprehensive flow analysis is carried out at various velocities and angle of attacks using computational fluid dynamics (CFD) and the results were interpreted and compared with the experimental values. This study shows that there is a significant improvement in the aerodynamic performance of the curved leading edge wing over the wing with rectangular planform.