• Title/Summary/Keyword: 항공유

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Nonlinear Analysis of Inflatable Membrane Structures with Wrinkling Effect (주름 효과를 고려한 팽창형 막 구조물의 비선형 해석)

  • Roh, Jin-Ho;Yoo, Eun-Jung;Han, Jae-Hung;Lee, In;Kang, Wang-Gu;Yeom, Chan-Hong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.12
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    • pp.33-38
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    • 2005
  • The large deformation of inflatable membrane structure is numerically and experimentally considered in this paper. The numerical algorithm of wrinkling based on Miller and Hedgepeth membrane theory is developed using user material(UMAT) subroutine written by FORTRAN. Wrinkled area and deformed shapes of inflatable membrane structures are investigated by using ABAQUS with UMAT subroutine of wrinkling algorithm.

A study on the physical properties effect of additive on the Jet A-1 (첨가제를 이용한 Jet A-1 연료의 물성증대 효과 연구)

  • Joo, Hyeong-Uk;Joo, Hyun-Hye;Lee, Ji-Hun;Kwon, Tae-Soo;Han, Jeong-Sik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.702-704
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    • 2011
  • For the representative of the poor performance of liquid fuel(Jet A-1), the physical properties effests of different additive ratios in the liquid fuel have been investigated. The mixed liquid fuel could be analyzed by principal factor of liquid fuel such as, density, viscosity and caloric value. This additives will be usefully applied to high energy density liquid fuel development.

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Ground Test of the Flight Control System Using PC104 (PC104를 이용한 비행제어 시스템 개발을 위한 지상시험)

  • Heo, Chi-Hoon;Roh, Min-Shik;Cho, Kyeum-Rae;Lee, Dae-Woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.5
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    • pp.452-459
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    • 2007
  • This paper presents the flight control system using a PC104 with GPS and IMU. This System includes an Auto/Manual conversion module by PIC16 for safety, and homing type guidance algorithm to flight toward a scheduled target. We verify the performance of the flight control system via ground test, and present the possibility of application into UAV control system via comparison with the commercial system.

The Requirements of Payload for the UAV (무인기용 임무장비 선정시 요구사항)

  • Kim, Joong-Wook
    • Aerospace Engineering and Technology
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    • v.6 no.2
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    • pp.245-249
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    • 2007
  • The objective of the UAV removes the life loss of the pilot who is the maximum weak point of the manned reconnaissance aircraft, accomplishes the reconnaissance it is an aircraft for. The camera which will confirm the pilot substitution reconnaissance result which stands is necessary, we should confirm; the target which this camera probably is what. The report which described like this demand condition against the consideration fact which is necessary to the selection of the image sensory device which is a camera which with character will be applied in UAV.

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Effects of Mold Time on Swelling of Natural Rubber Sponge by 2-Step Foaming (2단발포에서 금형시간이 천연고무 스폰지의 팽윤에 미치는 효과)

  • Lee, Hwan-Kwang
    • Proceedings of the KAIS Fall Conference
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    • 2008.11a
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    • pp.335-338
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    • 2008
  • 2단발포에서 금형시간이 천연고무(NR) 스폰지의 팽윤에 미치는 효과를 검토하였다. Kneader와 Rollmill을 사용하여 NR컴파운드를 제조하고 높은 압력조건의 1차금형에서 부분가교시킨 후 대기압의 2차 금형에서 발포와 가교를 완성시켰다. NR스폰지의 겉보기밀도를 측정하고 주사전자현미경을 사용하여 셀구조를 관찰하였다. 얻어진 스폰지에 대하여 실온에서 톨루엔, 이소옥탄, 항공유에 의한 팽윤거동을 조사하였다. 1차금형시간이 증가하면 NR스폰지의 겉보기밀도가 증가하고 팽윤비가 감소하였다. 2차금형시간이 증가하면 NR스폰지의 겉보기밀도가 감소하고 팽윤비가 증가하였다. 용매의 접촉에 의한 NR 스폰지의 부피팽윤비를 높이기 위하여 금형에서 동시에 발생하는 발포제의 분해반응과 NR의 가교반응을 적절히 조절하는 것이 중요하다.

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Derivation and Verification of the Relative Dynamics Equations for Aerial Refueling (공중재급유를 위한 상대운동방정식 유도 및 검증)

  • Jang, Jieun;Lee, Sangjong;Ryu, Hyuk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.4
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    • pp.1-10
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    • 2013
  • This paper addresses the derivation of 6-DOF equation of Tanker and Receiver's aircraft for aerial refueling. The new set of nonlinear equations are derived in terms of the relative translational and rotational motion of receiver aircraft respect to the tanker aircraft body frame. Further the wind effect terms due to the tanker's turbulence are included. The derivation of absolute dynamic equation for tanker aircraft written in the inertial frame is calculated from the relative dynamics equations of receiver. The derived relative and absolute equations are implemented the simulation in the same flight conditions to verify the relative motion and compare the trim results by using the MATLAB/SIMULINK program.

The Effectiveness of Independent V&V in System Development Project (시스템 개발 프로젝트에서의 Independent V&V 효과도)

  • Kim, Yeong-Hun;Yu, Byeong-Seon;Gang, Ja-Yeong
    • 한국항공운항학회:학술대회논문집
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    • 2015.11a
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    • pp.277-281
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    • 2015
  • 시스템 엔지니어링은 현대사회에서 성공적인 프로젝트의 실현을 가능케 하는 하나의 개발 방법론으로 선진국에서는 정부, 공공기관, 방위산업체, 민수산업체 등에서 도입하여 시스템 개발 프로젝트를 전수명주기에 걸쳐 효율적이고 체계적으로 관리하고 있다. 시스템 검증 및 확인 프로세스는 시스템 엔지니어링의 핵심 요소 중의 하나로서 고객이 요구하는 시스템 요구사항들이 프로젝트 전수명주기에 걸쳐 올바르게 충족이 되었는가를 입증하고 확인하는 일련의 활동으로 구성된다. 본 논문에서는 국외의 연구 사례들을 조사하여 이러한 검증 및 확인 활동의 독립성이 시스템 개발 사업에 어떠한 긍정적인 효과를 발생시키는지를 분석하였다.

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A Design for GPS Instrument Approach Procedure in Cheju International Airport (제주국제공항에 대한 GPS 계기접근절차의 고안)

  • Yoo, B.S.;Song, B.H.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.7 no.1
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    • pp.41-55
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    • 1999
  • In case of KOREA, many difficulties are expected for pilots to adapt to the flight operational environment changes which we will meet suddenly in anytime of the future as the operating plan for GPS is not fully prepared yet. It is because GPS operation is rather difficult compared to other navigation equipments, and it takes much time and experience to be familiar with GPS instrument approach procedure. First of all, it is keenly required to establish GPS instrument approach procedure for the local airports to be familiar with GPS instrument approach procedure. We would like to introduce GPS instrument approach procedure for the Cheju International Airport as a basic model to help you to understand it.

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The Effect of Partial Blockage of Flow Passage to Performance Change of a Liquid Rocket Engine (유로 단면 부분 폐쇄가 액체로켓엔진 성능 변화에 미치는 영향)

  • Cho, Won Kook
    • Journal of Aerospace System Engineering
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    • v.9 no.4
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    • pp.67-72
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    • 2015
  • The analysis has been performed on the blockage effect at the propellant flow passage in a liquid rocket engine. This simulates an example of emergency situation where flow passage is partially blocked. The analysis method has been validated by predicting the pump head and flow rate within 1% precision against the measured data of turbopump-gas generator coupled test. When the oxidizer passage is reduced it is predicted that the mixture ratio decreases, the oxidizer pump head increases and the gas generator pressure increases. When the fuel passage is reduced it is predicted that the mixture ratio increases, fuel flow rate decreases and the fuel pump head increases.

Individual Ortho-rectification of Coast Guard Aerial Images for Oil Spill Monitoring (유출유 모니터링을 위한 해경 항공 영상의 개별정사보정)

  • Oh, Youngon;Bui, An Ngoc;Choi, Kyoungah;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1479-1488
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    • 2022
  • Accidents in which oil spills occur intermittently in the ocean due to ship collisions and sinkings. In order to prepare prompt countermeasures when such an accident occurs, it is necessary to accurately identify the current status of spilled oil. To this end, the Coast Guard patrols the target area with a fixed-wing airplane or helicopter and checks it with the naked eye or video, but it was difficult to determine the area contaminated by the spilled oil and its exact location on the map. Accordingly, this study develops a technology for direct ortho-rectification by automatically geo-referencing aerial images collected by the Coast Guard without individual ground reference points to identify the current status of spilled oil. First, meta information required for georeferencing is extracted from a visualized screen of sensor information such as video by optical character recognition (OCR). Based on the extracted information, the external orientation parameters of the image are determined. Images are individually orthorectified using the determined the external orientation parameters. The accuracy of individual orthoimages generated through this method was evaluated to be about tens of meters up to 100 m. The accuracy level was reasonably acceptable considering the inherent errors of the position and attitude sensors, the inaccuracies in the internal orientation parameters such as camera focal length, without using no ground control points. It is judged to be an appropriate level for identifying the current status of spilled oil contaminated areas in the sea. In the future, if real-time transmission of images captured during flight becomes possible, individual orthoimages can be generated in real time through the proposed individual orthorectification technology. Based on this, it can be effectively used to quickly identify the current status of spilled oil contamination and establish countermeasures.