• Title/Summary/Keyword: icing

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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.

Study for Certification of Aircraft De-icing System (항공기 제빙 시스템의 인증에 대한 연구)

  • Jun, Jonghyub
    • Journal of Aerospace System Engineering
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    • v.6 no.2
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    • pp.7-12
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    • 2012
  • De-icing system is essential for any aircraft to fly in icing conditions. So there are two kinds of aircraft-those that are certificated for flight in icing conditions and those that are not. Icing certification involves a rigorous testing program, and relatively few light aircraft carry this approval. From a legal perspective, aircraft that do not have all required ice protection equipment installed and functional are prohibited from venturing into an area where icing conditions are known. There are a few kinds of de-icing system. It is necessary to review the systems in point of aircraft certification considering the operational and safety issues.

Icing Loads on Fixed Cables: I. Laboratory Experiments (고정케이블에 작용하는 Icing 하중 :I. 실험)

  • ;Ettema, R
    • Water for future
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    • v.29 no.1
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    • pp.249-263
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    • 1996
  • Presented herein are the results of a laboratory study on structural loads (icing weight and wind loads) associated with icing formation on rigidly fixed, circular power-transmission cables and cylinders. The experiments were carried out using movable wind tunnel under two different conditions: refrigerated and non-refrigerated conditions. Temporal evolution of icing loads were determined in the refrigerated laboratory and wind loads for icings at several stages of icing formation were measured in the non-refrigerated laboratory.

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Icing Loads on Fixed Cables: II. Determination of Proper Length Scale (고정케이블에 작용하는 Icing 하중: II. 적절한 특성길이의 결정)

  • Yoon B. M.;Pokorny, M.;Ettema, R.
    • Water for future
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    • v.29 no.2
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    • pp.191-198
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    • 1996
  • Attempts were made to determine a proper length scale representing characteristics of icing geometry. It was difficult to determine a single length scale especially for glaze icings because of their shape complexity. However, use of icing length, which is defined as the length of icing normal to the wind, as a characteristic length is suggested rather than the cylinder or cable diameter.

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A Study on the Korea Weather Environment for Icing Airworthiness of Military Helicopter (군용헬기 결빙 감항인증을 위한 국내 기상환경에 관한 연구)

  • Hur, Jangwook;Shin, Baekcheon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.3
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    • pp.304-310
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    • 2014
  • Based on atmosphere weather data by balloon in Osan and Gwangju area, if icing condition occurs in weather environment of altitude range where helicopter is operated was analyzed in quantitative way. Yearly icing occurrence frequency for daytime during recent three years was average 102 days in Osan, average 91 days in Gwangju. Icing weather environment to highly affect operation of helicopter varies a little according to analysis methods but icing intensity at MDT level was calculated in all the methods, and 14.5~38 times was suggested in Osan; 2.5~30 times in Gwangju. Icing at MDT level was calculated in common in all the analysis methods through wide periods such as Jan., Feb., Mar., and Nov. in Osan. In Gwangju, icing at MDT level was suggested focusing on Jan. only. Therefore, military helicopter developed in Korea is required to strive obtaining certificate of airworthiness about icing condition at MDT level for implementation of perfect operational mission and safe operation.

Icing Recovery Method Effect on Blood Lactate and Heart Rate after Sports Climbing

  • KIM, Myung Gyun;LEE, Dong Geun;MOON, Hwang Woon
    • Journal of Sport and Applied Science
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    • v.4 no.1
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    • pp.9-14
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    • 2020
  • The purpose of this study is to investigate the effect of ICING recovery method after sports climbing to blood lactate concentration and heart rate. The subjects were 12 male 20s undergraduate students (ICING group of 6, Control group of 6). Blood lactate concentration and heart rate were measured before climbing, after climbing, 5-minute recovery and 10minute recovery. Heart rate were also measured during the climbing. The subjects performed climbing 3 times. Data were analysed by SPSS 20.0. To compare blood lactate concentration and heart rate among groups, the independent samples t-test was employed using an alpha level of .05. Mean and standard deviations were computed. Results show that there is no significant difference between the icing group and non-icing group. Yet, the differences of blood lactate concentration were observed between groups. Blood lactate concentration of icing group was significantly higher than non-icing group in the condition of 1st climbing. Blood lactate concentration of non-icing group was significantly higher than icing group in 2nd 10-minute recovery. ICING recovery method is shown to be not significantly effective to blood lactate concentration and heart rate. This could be comprehended that long-term high-intensity (70% of 1RM) exercise can be prepared for the further research.

A Study on the Parameters for Icing Airworthiness Flight Tests of Surion Military Helicopter (수리온 군용헬기의 결빙 감항인증 비행시험을 위한 파라미터 고찰)

  • Hur, Jang-Wook;Kim, Chan-Dong;Jang, Jae-Sang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.6
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    • pp.526-532
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    • 2015
  • In order to relieve limitation of flight operation under icing condition and verify its operation in adverse weather condition for Surion, military helicopter developed in Korea, airworthiness certification in icing condition is required. The process of Surion icing certification should be considered by implementation of four methods by step such as CFD analysis, simulated flight tests, artificial icing flight tests, and natural icing flight tests. For Surion icing flight tests, these are required 20~30 sorties and 20~23 hours in artificial icing condition; 20~30 sorties and 20~22 hours in natural icing condition. In addition, to proceed with efficient flight tests, it is necessary to implement artificial icing flight tests in LWC $0.5{\sim}1.0g/m^3;$ natural icing flight tests in less than LWC $0.5g/m^3$.

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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The Analysis of the characteristics of Korean peninsula Aircraft Icing Index using KWRF (KWRF를 활용한 한반도 착빙 지수 특성 분석)

  • Kim, Young-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.18 no.3
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    • pp.42-54
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    • 2010
  • The purpose of this study is to analyze the aircraft icing index of Korean peninsula using the numerical weather prediction model, KWRF and pilot weather report data. As comparing the pilot weather report data with the calculated icing index using the KWRF model result, SCLW, RAP, and AFGWC index are more useful than any other index, and IC2, NAWAU, and RSID index are different case by case. But IC1, SID1 and SID2 index show that these overestimated severe icing in every vertical level. Through this icing study, it is expected that this study will help to develop the proper icing index of Korean peninsula.

The Study of FAA's certification policy for approving the ground use of deicing/anti-icing fluids on airplane (항공기용 결빙방지액의 지상 사용승인을 위한 FAA의 최근 인증정책 연구)

  • Kim, You gwang
    • Journal of Aerospace System Engineering
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    • v.7 no.3
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    • pp.51-57
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    • 2013
  • This study describes the Federal Aviation Administration(FAA) certification policy for approving the use of Type II, III, and IV deicing/anti-icing fluids on small category airplanes. These fluids can be characterized as non-Newtonian, pseudo-plastic fluids, also known as "thickened" fluids. Deicing fluids are used before takeoff to remove frost or ice contamination, while anti-icing fluids are used before takeoff to prevent frost or ice contamination from occurring for a period of time(referred to as "holdover time") after application. Thickened deicing/anti-icing fluids can affect airplane performance and handling characteristics and their residue may cause stiff or frozen flight controls. This study also describes an approval process that may be used by type certificate holders and applicants for a type certificate under parts 23 to support operational use of these fluids on their airplanes.