• Title, Summary, Keyword: 회전익

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How to Manage Aging Aircraft (노후 항공기 관리방안)

  • Choe, Se-Jong;Kim, Cheon-Yong
    • 한국항공운항학회:학술대회논문집
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    • pp.202-208
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    • 2016
  • 최근 5년간 발생한 국적 항공기 사고 23건 중 헬기사고가 16건으로 전체 항공사고의 70%를 차지한다. 현재 국내에서 고정익 항공기 549대, 회전익 항공기 186대가 각각 운영(군 경찰 보유헬기 제외)되고 있음을 감안하면 회전익 항공기 사고가 훨씬 높은 편이며, 고정익 항공기 가동시간에 비하여 가동률이 매우 낮은 회전익 항공기를 고려하면 비행시간당 항공기 사고 비율은 회전익 항공기가 월등하게 높은 편이다. 또한 고정익 항공기의 평균기령은 10.9년인데 비하여 산림항공본부를 비롯한 헬기운영업체에서 운영 중인 회전익 항공기의 평균기령은 18.9년으로 회전익 항공기가 전체적으로 노후화 되어 있으나, 국적항공사에 운영 중인 노후 항공기 관리프로그램을 회전익 항공기 운영사에서는 운영하지 않고 있다. 따라서 본 연구를 통하여 노후 항공기 운영현황을 검토하여 노후 회전익 항공기 운영기준을 수립하고 노후 회전익 항공기의 정비프로그램을 정립하여 회전익 항공기의 지속감항성을 확보할 수 있는 방안과 수명주기 설정을 마련하고자 한다.

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Study on Determination Principal Direction for Composite Rotor Blades (복합재료회전익의 주축계 결정화에 관한 연구)

  • 유용석;이종범;정경렬
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.354-359
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    • 1995
  • 회전익의 소재로 복합재료를 선택하게 됨에 따라 헬리콥터의 유지, 보수 및 성능에서 유리하게 되었지만 허브 형태의 간소화로 인하여 해석상의 어려움은 확대 되었다고 할 수 있을 것이다. 따라서 회전익의 단면특성은 더욱 중요한 의미를 갖게 되었다. 회전익의 단면특성을 결정하기 위해서 우선적으로 각 방향운동의 연성항을 소거하는 것이 계산상 유리하고 따라서 관성주축방향을 결정하는 것이 중요하다. 그러나 회전익의 익형이 대칭형이 아니고 복합한 재료로 구성되어 있을 뿐 아니라 효율의 극대화를 위하여 축방향을 따라 비틀림을 부여하고 있기 때문에 관성주축의 방향을 결정하는데 많은 어려움이 존재한다. 따라서 본 연구에서는 실제 회전익을 그 연구 대상으로 회전익 단면의 등가강성행렬을 추출하고 외팔보의 공학이론과 회전행렬을 이용하는 방법으로 관성주축방향을 결정하는 방법을 제시하였다. 해석방법의 타당성을 확보하기 위하여 엄밀해를 알고 있는 간단해 단면을 갖는 외팔보를 이용하여 검증하였다. 이러한 방법은 관성주축방향을 결정하는 새로운 프로그램의 개발이라는 부담을 최소화 하였을 뿐 아니라, 해석방법 자체가 가지는 간편성으로 인하여 많은 시간과 노력을 줄일수 있을 것으로 기대된다.

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A Research on the Improvement of Human Factors for the Prevention of the Helicopter Accidents (회전익 항공기 사고예방을 위한 인적요인 향상에 관한 연구)

  • Choe, Jin-Guk;Yu, Tae-Jeong
    • 한국항공운항학회:학술대회논문집
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    • pp.79-83
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    • 2016
  • 1990년부터 14년간 총 65건의 회전익 사고가 발생하여 연 평균 4.6건의 사고가 발생하였다. 항공대국으로 안전한 수준에 이르기 위하여 회전익 항공기 사고의 잠재적 조건 선행 분석자료 및 연구결과 등을 활용하여 회전익 항공기 항공안전대책을 살펴보았다. 소방항공의 경우 인적요인이 사고 발생원인의 57%로 주 요인으로 나타났으며, 국가기관에서도 2000년 이후 사고 중에서 인적요인이 주 요인으로 인적요인이 중요한 개선대상으로 밝혀졌다. 항공안전 전문가들과 인터뷰를 실시하여 회전익 항공기의 잠재 조건에 대해 논의하였다.

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A Study on the Icing Certification of Rotorcraft (회전익 항공기의 결빙 인증에 대한 연구)

  • Lee, Hae-Sun;Park, Jong-Hyuk
    • Aerospace Engineering and Technology
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    • v.7 no.2
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    • pp.196-204
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    • 2008
  • Modem rotorcraft is required to have the capability to operate in all-weather conditions. Also icing condition is important issue to aircraft safety and certification. And rotorcraft icing research has come a long way during the past few decades. The aircraft icing is the most difficult to handle. So, icing-related accidents, incidents and operating problems still occur regularly in service, despite improvements in design and test techniques. By reviewing icing certification requirement of FAR(Federal Aviation Regulations) and KAS(Korean Airworthiness Standard), this paper describes methods how to demonstrate safety in the flight and consideration of icing when rotorcraft is required TC(Type Certification).

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Extension Feasibility on Replacement Cycle of Rotor Blade Equipped for Low Pressure First Stage in a 150 MW Gas Turbine (150 MW급 가스터빈 저압 1단 회전익 교체주기 연장 가능성 연구)

  • Lim, Jong-Ho;Lee, Jae-Heon
    • Plant Journal
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    • v.9 no.4
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    • pp.31-36
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    • 2013
  • In order to extend a hot gas parts replacement cycle of a gas turbine, blade row 1 from low pressure turbine, which has a significant impact on the cycle, has been selected from stored set after one cycle use. Taking into account the status of the first stage moving blade in LP turbine operated more than 27,000 equivalent operating hours(EOH) and the replacement cycle in the same type of gas turbine, the replacement of the high temperature components installed on the GT, a study subject, can be extended from 24,000 to 27,000 EOH.

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Development of European Rotorcraft in 21st Century (21세기 유럽의 회전익 개발 동향 분석)

  • Oh, Sejong;Park, Donghun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.8
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    • pp.679-686
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    • 2018
  • In previous paper[1], the authors had compared the current status of European and US rotorcraft development status. In this paper, more detailed procedures have been studied how the European rotorcraft technologies are developed preparing for 21 st century to be more competitive to US. For the systematic procedure to develop next generation aviation technologies including rotorcraft, the pan-European organization, ACARE, was established, and proposed major research agenda for next generation aviation technologies and businesses. Based on the proposed research agenda, all the R&D programs supported by EU are reorganized to be more efficient and competitive. The procedures for the rotorcraft technologies are, first, cabin noise/vibration reduction program (FRIENDCOPTER), second, core technologies to increase of rotor efficiencies and reduce rotor noise (GRC), and then finally to develop fast/long-range next generation rotorcraft (Fast Rotorcraft). As mentioned in previously, all the R&D procedure has to satisfy basic research agenda especially the environmental impact. With theses procedure, the European rotorcraft business had successful achievements not only in current and future market share, but also preparing for next generation rotorcraft platform such as compound and tilt-rotor rotorcraft satisfying market needs.

Development of Preliminary Conceptual Design/ Comprehensive Analysis Programs for Next Generation Rotorcraft (차세대 회전익 기본개념설계/통합해석 프로그램의 개발)

  • Oh, Sejong;Park, Donghoon;Ji, Hyung Min
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.1
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    • pp.75-84
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    • 2021
  • The authors had presented two previous papers[1,2] on Helicopter/Rotorcraft develoment in Europe and US. Meanwhile, the next generation rotorcrafts, currently under development in US and Europe, have new configurations (tilt-rotor, coaxial, compound) of rotor-type vertical takeoff/landing rotorcrafts to overcome the disadvantages of traditional helicopters. For developing these new types of rotorcrafts, the upgraded conceptual design/comprehensive programs are required. In US and Europe, they are already developing new program tools with their technologies and database obtained during more than last half centuries. For us, many academia, research institutes and industrial engineers have experienced and developed core technologies on rotorcrafts (aerodynamics, structural analysis, flight dynamics, and noise analysis etc.) comparable to US and Europe during last couple of decades of developing helicopters and various configurations of rotorcrafts. In this paper, the pros and cons of conceptual design/comprehensive tools currently used in US and Europe have been summarized. Furthermore, the possibilities and problems to develope our own design and analysis tools have been studied.

Two-Dimensional Flow Behavior Through a Stage of an Axial Compressor (축류 압축기내의 2차원 유동 특성)

  • Hong, Seong-Hun;Baek, Je-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.8
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    • pp.2561-2571
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    • 1996
  • The flow in the turbomachinery is very unsteady due to the stator-rotor interaction. It has been indicated that the stator-rotor interaction has three distinct causes of unsteadiness: that is, the viscous vortex shedding, wake rotor interaction and potential stator-rotor interaction. In this paper, the mechanism of unsteady potential interaction and wake interaction in the stator-rotor stage flow is numerically investigated in two-dimensional view point. The numerical technique used is the upwind scheme of Van Leer's Flux Vector Splitting(FVS) and cubic spline interpolation is applied on zonal interface. Then, the flow field of a compressor stage composed of NACA 65410 is analyzed. Flow fields are found to be simulated reasonably by this method and the sensitivity due to back-pressure variation is more stronger than rotor-velocity variation.

Accuracy Assessment of Parcel Boundary Surveying with a Fixed-wing UAV versus Rotary-wing UAV (고정익 UAV와 회전익 UAV에 의한 농경지 필지경계 측량의 정확도 평가)

  • Sung, Sang Min;Lee, Jae One
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.535-544
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    • 2017
  • UAVs (Unmanned Aerial Vehicle) are generally classified into fixed-wing and rotary-wing type, and both have very different flight characteristics each other during photographing. These can greatly effect on the quality of images and their productions. In this paper, the change of the camera rotation angle at the moment of photographing was compared and analyzed by calculating orientation angles of each image taken by both types of payload. Study materials were acquired at an altitude of 130m and 260m with fixed-wing, and at an altitude of 130m with rotary-wing UAV over an agricultural land. In addition, an accuracy comparison of boundary surveying methods between UAV photogrammetry and terrestrial cadastral surveying was conducted in two parcels of the study area. The study results are summarized as follows. The differences at rotation angles of images acquired with between two types of UAVs at the same flight height of 130m were significantly very large. On the other hand, the distance errors of parcel boundary surveying were not significant between them, but almost the same, about within ${\pm}0.075m$ in RMSE (Root Mean Square Error). The accuracy of boundary surveying with a fixed-wing UAV at 260m altitude was quite variable, $0.099{\sim}0.136m$ in RMSE. In addition, the error of area extracted from UAV-orthoimages was less than 0.2% compared with the results of the cadastral survey in the same two parcels used for the boundary surveying, In conclusion, UAV photogrammetry can be highly utilized in the field of cadastral surveying.

회전익 항공기 내충돌성 설계 기준동향

  • Kim, Seong-Gyeom
    • Current Industrial and Technological Trends in Aerospace
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    • v.5 no.1
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    • pp.104-111
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    • 2007
  • 내충돌성(crashworthiness)은 항공기 추락시 탑승객을 보호할 수 있는 항공기와 그 내부 시스템 및 구성품의 성능으로 정의할 수 있다. 민간 항공 분야에서 내충돌성에 대한 체계적인 연구가 시작된 것은 1980년대로서 90년대에 이르러서야 감항 기준으로서 완성되게 된다. 항공기의 안전성과 관련된 주요 설계 요건들이 이미 50-60년대에 기본적인 틀을 갖추었다는 점을 감안하면 내충돌성과 관련된 설계 요구조건은 상대적으로 새로 운 설계 개념으로 생각할 수 있다. 본 논문에서는 회전익 항공기를 중심으로 내충돌성 확보를 위해 고려해야 할 사항을 살펴보고, 현재 민간 회전익 항공기에 적용되고 있는 주요한 내충돌성 설계기준을 소개하도록 한다.

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