• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.151-155
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• 2020

In this study, the velocity distribution and pressure of the flow with the shape of the aircraft were analyzed to investigate its flight performance. In order to compare the flow rate and its pressure applied on the surface of airplane each other, models A and B have the blunt and sharp shapes as the distinctive shapes of airplanes. It can be inferred that the lower the maximum speed of the flow around the airplane, the less resistance the navigation produces, the less fuel consumption, which is more efficient for the sharp model B than the blunt model A. As the result of this study, the wing area and the head part of the body should be designed to withstand the pressure greater than the body. It is shown that the sharp model B can withstand more pressure due to flow than the blunt model A.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.779-787
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• 2013

The effects of various nozzle configurations on infrared signature are investigated for the purpose of analysing the infrared signature level of aircraft propulsion system. A virtual subsonic aircraft is selected and then a circular convergent nozzle, which meets the mission requirements, is designed. Convergent nozzles of different configurations are designed with different geometric profiles. Using a compressible Navier-Stokes-Fourier CFD code, an analysis of thermal flow field and nozzle surface temperature distribution is conducted. From the information of plume flow field and nozzle surface temperature distribution, IR signature of plume and nozzle surface is calculated through the narrow-band model and the RadThermIR code. Finally, qualitative information for IR signature reduction is obtained through the analysis of the effects of various nozzle configurations on IR signature.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.26-32
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• 1992

세계적으로 항공기 사고의 통계적 분석에 의하면 항공기 운용자의 인적과실(Human error)로 인한 항공기 사고가 약 70% 이상으로 보고되고 있다. 항공기 운용자의 인적과실에 기인한 요인들 중에서 운용자의 작업량, 작업공간, 작업환경, 인체크기, 인체 생리, 인간 심리 및 습관 등을 항공기 설계단계에서 고려하지 못한 요인이 대부분이다. 일반적으로 항공기 비행품질(Flying qualities)의 영향을 주는 설계분야는 크게 세가지로 항공기 형상(Configuration), 조종체계(Control system)및 조종실 배치(Cockpit layout)로 분류된다. 이들 세가지 설계분야 중에서 조종실의 운용자 인간공학적인 요구 사항을 고려하지 않으면 항공기 운용성 품질중에서 삼분의 일이 감소될 수 있다. 그리고 항공기 개발시에 전담하는 항공기 설계 분야별로 구분하고 그 전담설계 부서들과 인간공학적 조종실 설계 전담 부서가 항공기 비행 품질 및 운용자 인적과실(Human error)에 미치는 영향을 분석하고 인간공학의 중요성을 강조한다. 항공기를 개발할때에 개발자는 그 항공기를 운용하는 운용자의 인체, 생리, 심리, 습관 등을 고려 하여 항공기 조종실의 인간공학적 최적화 설계 및 배치 (Design and layout)를 개발초기단계부터 항공기를 설계할때에, 그 항공기의 조종실 품질은 조종사가 항공기 비행 임무를 수행할때에 항공기 비행을 위한 용이한 정보 인식(Sencing), 용이한 정보 결심(Deciding) 및 용이한 조종(Manipulating)의 특성을 조종사에게 제공할 때 항공기 비행 품질이 좋아질 것이다.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.29-31
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• 2015

항공레저 스포츠의 급속적인 활성화 추세에 따라 국내 최초로 스포츠급 경항공기 KLA-100이 개발중이다. 본 개발 과제를 통해 경항공기 분야의 독자 개발과 인증에 필요한 기술을 확보하고 국내 경항공기 개발의 토대를 마련하기 위하여 그동안 축적된 항공기 개발 기술을 최대한 활용하여 해외 경항공기 개발 전문회사의 기술지원을 통해 항공기 개발 완성을 그 목표로 노력하고 있다. 본 연구에서는 현재 상세설계가 완료된 경항공기의 형상해석 수행 결과를 소개하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.530-536
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• 2010

In-flight icing is a critical technical issue for aircraft safety and, in particular, ice accretions on aircraft surfaces can drastically impair aerodynamic performances and control authority. In order to investigate icing effects on the aerodynamic characteristics of KC-100 aircraft, a state-of-the-art CFD code, FENSAP-ICE, was used. A main wing section and full configuration of KC-100 aircraft were considered for the icing analysis. Also, shapes of iced area were calculated for the design of anti-/de-icing devices. The iced areas around leading edge of main wing and horizontal tail wing were observed maximum 7.07% and 11.2% of the chord length of wing section, respectively. In case of wind shield, 16.7% of its area turned out to be covered by ice. The lift of KC-100 aircraft were decreased to 64.3%, while the drag was increased to 55.2%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.16-26
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• 2005

The aerodynamic design of a proprotor for the Smart UAV adopting tiltrotor aircraft concept is conducted in this study. Since proprotor of tiltrotor aircraft is operated at both rotary and fixed wing mode with single configuration rotor, the proprotor has to be designed to meet performance requirements for both flight modes. The aerodynamic design of proprotor is accomplished by combining three sources of data - the proprotor performance data, the aerodynamic data of vehicle, and the performance data of engine. The performance analysis code for proprotor is based on the combined momentum and blade element theory and validated by comparison with the TRAM data. In order to design configuration for a proprotor satisfying requirements for both rotary and fixed wing mode, various kind of performance maps are constructed for many performance and configuration parameters. From the analysis the twist angle of 38 degrees and the solidity of 0.118 are decided to be the optimal geometric parameters for both operating conditions.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.554-559
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• 2016

본 논문은 EDISON CFD를 사용하여 스포일러가 장착된 무미익 BWB UCAV에 대하여 이차원 유동해석을 수행하였다. 무미익 형상은 일반적인 항공기보다 롤과 요 방향의 안정성과 조성성에 있어 불리한 특징을 갖는데 특히 이 착륙 시 고 받음각의 영역에서 발생하는 Pitch-up 현상이 항공기 안정성에 문제를 야기한다. 수직 미익 부재와 pitch-up 현상으로 인한 BWB형상의 UCAV가 지니는 단점을 보완하기 위해서 스포일러가 장착된 형상이 적용되기도 한다 본 연구에서는 윗면과 아랫면에 스포일러가 장착된 경우에 대해 전산유동해석을 수행하였다. 해석결과 윗면의 스포일러는 양력의 감소와 항력의 증가를 야기했으며, 아랫면의 스포일러는 양력과 항력을 모두 증가시켰다. 피칭모멘트의 경우 아랫면의 스포일러가 저받음각에서 안정성을 증가시켰다.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.3
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• pp.1-7
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• 2002

During the preliminary design phase of aircraft development, it is necessary to evaluate many potential engine/airframe combinations to determine the best solution to given set of mission requirements and it is very important to establish a methodology to calculate precisely engine installed performance. It was carried out to calculate turbofan engine installed performance of a supersonic aircraft for a given engine/aircraft configuration. Thus "Thrust minus drag accounting system" was introduced to identify and calculate the elements of installed thrust or installed propulsive force by using the database based on wind tunnel test data. This paper describes the calculated results of installed thrust of turbofan engine for a supersonic aircraft. aircraft.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1066-1072
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• 2009

A panel method based on potential flow theory is developed for the steady/unsteady aerodynamic analysis of arbitrary three-dimensional Blended Wing Body aircraft. The panel method uses the piecewise constant source and doublet singularities as a solution. This potential based panel method is founded on the Dirichlet boundary condition and coupled with the time-stepping method. The present method uses the time-stepping loop to simulate the unsteady motion of the aircraft. The present method can solve the three-dimensional flow over the complex bodies with less computing time and provide various aerodynamic derivatives to secure the stability of Blended Wing Body aircraft. That will do much for practical applications such as aerodynamic designs and analysis of aircraft configurations and flight simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.736-741
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• 2017

This paper examines the design for improving the wiper system of rotorcraft. During rotorcraft operation, the wiping performance and excessive clearance can decrease. The wiper system consists of a wiper arm assembly, motor, convertor and flex drive. If there is a problem with the wiper system, the operation ability decreases because the operation is restricted in a rainy environment. There are two main causes of the problem of the wiper system: the lifting forces acting on the wiper arm in aircraft flight and the excessive gap of the components. To remedy these two problems, the wiper arm was improved. The improvements included increased contact pressure on the wiper arm (spring tension), improved gear clearance, and material and shape changes. Durability test, aircraft ground test and flight test were carried out to verify the improved shape, and it was confirmed that the wiping performance and clearance problems were solved. Currently, the rotorcraft is operated without problem by applying the improved shape, and this design improvement process will be a useful reference for future rotorcraft development.