• Title/Summary/Keyword: super-cooled water droplet

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Super-cooled State Cloud Generation System Development for T-50 Supersonic Jet Trainer Icing Test (T-50 고등훈련기 빙결시험을 위한 과냉각구름 생성시스템 개발)

  • Lee, Cheol;Jeon, Cheol-Woo
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.6
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    • pp.580-586
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    • 2008
  • Icing cloud generation system was developed to perform the in-flight icing simulation test for T-50 Supersonic Jet Trainer on the ground. The developed system successfully generated the almost natural icing cloud in the super-cooled state (liquid state) below freezing point and with the required LWC (Liquid Water Content). For full-scale aircraft icing test, an icing scaling method was adopted due to the limitation of wind generation speed with open-circuit type blower and its applicability was experimentally verified. Under the required in-flight icing condition based on the icing scaling method, T-50 aircraft subsystems were successfully operated and functionally checked.

Development and Demonstration of 150W Fuel Cell Propulsion System for Unmanned Aerial Vehicle (UAV) (무인항공기용 150W급 연료전지 동력원 개발 및 실증)

  • Yang, Cheol-Nam;Kim, Yang-Do
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.4
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    • pp.300-309
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    • 2012
  • Long endurance is a key issue in the application of unmanned aerial vehicles. This study presents feasibility test results when fuel cell system as an alternative to the conventional engine is applied for the power of the UAV after the 150W fuel cell system is developed and packaged to the 1/4 scale super cub airplane. Fuel cell system is operated by dead-end method in the anode part and periodically purged to remove the water droplet in flow field during the operation. Oxygen in the air is supplied to the stack by the two air blowers. And fuel cell stack is water cooled by cooling circuit to dissipate the heat generated during the fuel cell operation. Weight balance is considered to integrate the stack and balance of plant (BOP) in package layout. In flight performance test, we demonstrated 4 times standalone take-off and landing. In the laboratory test simulating the flight condition to quantify the energy flow, the system is analyzed in detail. Sankey diagram shows that electric efficiency of the fuel cell system is 39.2%, heat loss 50.1%, parasitic loss 8.96%, and unreacted purged gas 1.67%, respectively compared to the total hydrogen input energy. Feasibility test results show that fuel cell system is high efficient and appropriate for the power of UAV.