• Title/Summary/Keyword: Mid-sized Aircraft

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AERODYNAMIC ANALYSIS OF A PITCH OSCILLATING MID-SIZED AIRCRAFT (피치 진동하는 중형항공기의 공력 특성 해석)

  • Lee, Yung-Gyo;Kim, Cheol-Wan;Ahn, Seok-Min
    • Journal of computational fluids engineering
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    • v.16 no.1
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    • pp.48-52
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    • 2011
  • Aerodynamic analysis was done for a fuselage and wing configuration of a mid-sized aircraft using unsteady 3-dimensional Navier-Stokes solver. Various turbulent models including a transitional SST were used to observe a dynamic stall as well as cruise characteristics. Also, different mesh moving methods were evaluated. Flow hysteresis which causes dynamic stall was investigated through flow field investigations.

DYNAMIC STALL ANALYSYS OF A MID-SIZED AIRCRAFT (중형항공기 동적 실속 특성 해석)

  • Lee, Yung-Gyo;Kim, Cheol-Wan;Ahn, Seok-Min
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.37-39
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    • 2010
  • Aerodynamic analysis was done for a fuselage and wing configuration of a mid-sized aircraft using 3-dimensional Navier-Stokes solver. Various turbulent models including a transitional SST were implemented to observe a dynamic stall as well as cruise characteristics. Also, different mesh moving methods were evaluated. Flow hysteresis which causes dynamic stall was investigated through flow field investigations.

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Development of Aircraft 2-Stage Differential GRA (항공기용 2단 차동 GRA 개발)

  • Lee, Kang-Hee;Im, Dae-Jin;Lee, Sun-Hong;Park, Seul-Ki;Choi, Jin-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.6
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    • pp.115-121
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    • 2016
  • The aircraft flight control system controls an aircraft's direction and flying attitude, and actuators are key components of control systems. Actuators can be classified as Geared Rotary Actuator (GRA) and Ball Screw Actuator (BSA). GRA is used in mid-sized aircraft, and BSA is used in larger aircraft. A two-stage differential GRA model was suggested in this paper, and structural analysis and performance tests were performed. According to the analysis and experiment, the stiffness of the two-stage differential GRA was 17.57% higher than that of the conventional GRA, and the structural safety was improved.

Subsonic/Transonic Airfoil Design Using an Inverse Method (Inverse 기법을 이용한 아음속/천음속 익형 설계)

  • Lee Jae Woo;Lee Young-Ki;Byun Yung-Hwan
    • 한국전산유체공학회:학술대회논문집
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    • 1998.05a
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    • pp.61-66
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    • 1998
  • An inverse method for the subsonic and transonic airfoil design was developed using the Euler equations. Two testcases were performed. One was a design of the supercritical airfoil, aiming to be used for the Korean mid-sized (100 passengers class) transport aircraft. The other was the design of an airfoil showing a good cruising performance (L/D ratio) in the high subsonic/transonic flow regimes. These testcases demonstrated the efficiency and the robustness of the developed method.

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Comparative legal review between national R&D projects and defence R&D programs - A study on improvement of royalty system for the promotion of aircraft industry - (국가연구개발사업 및 국방연구개발사업 간 비교법적 검토 - 항공기산업 진흥을 위한 기술료 제도 개선에 관한 연구 -)

  • Lee, Hae-Jun;Kim, Sun-Ihee
    • The Korean Journal of Air & Space Law and Policy
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    • v.35 no.1
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    • pp.153-180
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    • 2020
  • This study is meaningful in finding out what legal and policy issues need to be improved in order to foster the aircraft industry, which is relatively underdeveloped compared to the fact that some heavy industries, such as the automobile industry and shipbuilding industry, have achieved a high level of production and technology globally. Korea's aircraft industry has been growing at a slower pace than other industries, largely due to the country's economic growth and the lack of a market structure to properly use variables such as the level of development in related industries, aircraft technology and demand for aircraft manufacturing. While most industries are privately led by the market structure of the competition system, heavy industries such as the aircraft industry generally grow under the market structure of the incomplete competition system, because only by securing huge initial investment costs, high technology, and sufficient demand, they can maintain minimum economic feasibility. The Korean aircraft industry was focused on developing and mass-producing military aircraft focusing on military demand, but it sought to turn the tide by signing the BASA (Bileral Aviation Safety Agreement) with the U.S. A preliminary feasibility study was conducted in 2010 to develop next-generation medium-sized aircraft, but was cancelled due to differences in position with Canada's Bombardier, which is subject to the concourse, and Korea Aerospace Industries (KAI) is pushing for the production of Bombardier's Q400 license on its own. Compared to the mid-to-large sized civil aircraft that are facing difficulties in development, KAI and KARI are successfully developing technologies to unmanned aerial vehicles and civil helicopters. In addition, the unmanned aerial vehicle sector is not yet suitable for manufacturers that have an exclusive global influence, so we believe that it is necessary to pursue government-led research and development projects with a focus on the areas of commercial helicopters and unmanned aerial vehicles in order to foster the aircraft industry in the future. In addition, since military aircraft such as KT-1 and T-50 are currently being exported smoothly, and it cannot be overlooked that the biggest demand for aircraft manufacturing in the Korea is the military, it is necessary to push forward national R&D projects and defense R&D program simultaneously to enable both civilian-military development. However, there are many differences between the two projects in the way they are implemented, the department in charge and the royalty system. Through this study, we learned about the technology ownership and implementation rights of national R&D projects and defense R&D programs, as well as the royalty system. In addition, problems with the system were identified and improvement measures were derived.

Subsonic/Transonic Airfoil Design Using an Inverse Method (Inverse 기법을 이용한 아음속/천음속 익형 설계)

  • Lee Young-Ki;Lee Jae-Woo;Byun Yung-Hwan
    • Journal of computational fluids engineering
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    • v.3 no.1
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    • pp.46-53
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    • 1998
  • An inverse method for the subsonic and transonic airfoil design was developed using the Euler equations. Two testcases were performed. One was a verification of the method using the supercritical airfoil of the Korean mid-sized (100 passengers class) transport aircraft. The other was the design of an airfoil showing a good cruising performance (L/D ratio) in the high subsonic flow regime. These testcases demonstrated the efficiency and the robustness of the design method in the present study.

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A Study on the Necessity of Korea-MERCOSUR FTA and Policy Implications (한-MERCOSUR FTA의 필요성과 추진전략)

  • Jeong, Jae-Hwa
    • International Commerce and Information Review
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    • v.11 no.2
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    • pp.303-328
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    • 2009
  • MERCOSUR, which is the biggest economic community in the Latin America, has great potential as Korea's export market with 220 million population and 2.8 trillion$ GDP. In the midst of global economic crises, the importance of MERCOSUR is highlighted with relatively sound economic growth. The average tariff rate of MERCOSUR is 10.4~12.2% which is almost same as that of Korea(12.2%), but the tariff rates on Korea's main export items such as auto, display, digital camera, mobile phone are as high as 20~30%, which means that Korea-MERCOSUR FTA will result in substantial growth of Korea's export. In pursuing Korea-MERCOSUR FTA, cooperations in natural resources, agriculture, mid-sized aircraft, construction and green energy as well as liberalization of commodity market are very important for Korea. To realize Korea-MERCOSUR FTA, it is essential to overcome the objections from the manufacturing sectors of MERCOSUR. So it is desirable to aim relatively low in terms of the level of liberalization at the beginning, and expand corporate and industrial cooperation between Korea and MERCOSUR's manufacturing industries.

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토양 및 지하수 Investigation 과 Remediation에 대한 현장적용

  • Wallner, Heinz
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.44-63
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    • 2000
  • Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.

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