• Title/Summary/Keyword: Anti-Icing

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Study about the Standard of Anti-icing System Based on Geography and Geometric Designs (기하구조 및 지형적 요소를 고려한 융설시스템 설치 기준 정립에 관한 연구)

  • Lee, Dong-Hyun;Jeong, Won-Seok;Kim, Ji-Won;Ko, Seok-Beom
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.95-102
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    • 2011
  • Anti-icing system can immediately respond when snowing is expected or the snow comes down on the road surface. It has been recognized that the system can reduce traffic accidents and congestion by quickly removing the frozen road surface area. However, it is very difficult to implement this system due to the expensive equipment installation and operation cost, Recently, there was a developed program for predicting the freezing area using three-dimensional model and tracking the sun path. But, there is no objective analysis method and all developed approaches are different so that the general standard of anti-icing system is needed. In this study, we proposed the decision criteria for determining application priorities of the anti-icing system based on weather and road conditions, i.e., geometric and topographic conditions. Regional climate survey, topographical analysis, and dynamic vehicle simulation considered road geometry and skid resistance was conducted to standardize the installation method of anti-icing system.

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.

Indirect Verification of the Icing Test Condition Using Ice Thickness (얼음두께를 이용한 결빙시험조건의 간접 확인기법)

  • Kim, Yoo Kyung;Park, Nameun;Choi, Gio
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.11
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    • pp.944-951
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    • 2018
  • Artificial icing test and wind tunnel test can be performed to reduce the development period when a rotorcraft is required operation under icing situations. Artificial icing test of the KUH(Korean Utility Helicopter) was performed in advance to verify anti-icing and de-icing performance before natural icing test. Although high-precision sensor, the CCP(Cloud Combination Probe) is used to measure icing test condition parameters such as LWC(Liquid Water Content) and MVD(Median Volume Diameter), the measured values need to be verified in various methods due to the possibility of uncertainties which are the test atmosphere environment, sensor errors, and etc. The calculated LWC from the ice thickness cumulated on the fuselage of the KUH is compared to the measured value by CCP, and the results show the effective indirect method to check the test conditions.

Icing Characteristics in Liquid-Phase Injection of LPG Fuel (액상분사식 LPG 인젝터의 아이싱 생성 특성 및 억제 방법)

  • Lee, Sun-Youp;Kim, Chang-Up;Choi, Kyo-Nam;Kang, Kern-Yong
    • Journal of ILASS-Korea
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    • v.14 no.4
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    • pp.147-152
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    • 2009
  • Since a liquid-phase LPG injection system allows accurate control of fuel injection and increase in volumetric efficiency, it has advantages in achieving higher engine power and lower emissions compared to the mixer type LPG supplying system. However, this system also leads to an unexpected event called icing phenomenon which occurs when moisture in the air near the injector freezes and becomes frost around the nozzle hole due to extraction of heat from surrounding caused by instant fuel vaporization. As a result, it becomes difficult to control air/fuel ratio in engine operation, inducing exacerbation of engine performance and HC emission. One effort to mitigate icing phenomenon is to attach anti-icing injection tip in the end of nozzle. Therefore, in this study, the effect of engine operation parameters as well as surrounding conditions on icing phenomenon was investigated in a bench test rig with commercially-used anti-icing injection tips. The test results show that considerable ice was deposited on the surface near the nozzle hole of the anti-icing tip in low rpm and low load operating conditions in ambient air condition. This is because acceleration of detachment of deposited ice from the tip surface was induced in high load, high rpm conditions, resulting in decrease in frost accumulation. The results of the bench testing also demonstrate that little or no ice was formed at surrounding temperature below a freezing point since the absolute amount of moisture contained in the intake air is too small in such a low temperature.

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Investigation of the Performance of Anti-Icing System of a Rotorcraft Engine Air Intake (회전익기 공기흡입구 주위 방빙장치 성능 해석)

  • Ahn, Gook-Bin;Jung, Ki-Young;Jung, Sung-Ki;Shin, Hun-Bum;Myong, Rho-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.4
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    • pp.253-260
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    • 2013
  • Ice accretions on the surface around a rotorcraft air intake can deteriorate the safety of rotorcraft due to the engine performance degradation. The computational simulation based on modern CFD methods can be considered extremely valuable in analyzing icing effects before exact but very expensive icing wind tunnel or in-flight tests are conducted. In this study the range and amount of ice on the surface of anti-icing equipment are investigated for heat-on and heat-off modes. It is demonstrated through the computational prediction and the icing wind tunnel test that the maximum mass and height of ice of heat-on mode are reduced about 80% in comparison with those of heat-off mode.

An Investigation of Icing Effects on the Aerodynamic Characteristics of KC-100 Aircraft (KC-100 항공기의 표면발생 Icing 형상 및 공력 영향성 연구)

  • Jung, Sung-Ki;Lee, Chang-Hoon;Shin, Sung-Min;Myong, Rho-Shin;Cho, Tae-Hwan;Jeong, Hoon-Hwa;Jung, Jae-Hong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.6
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    • pp.530-536
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    • 2010
  • In-flight icing is a critical technical issue for aircraft safety and, in particular, ice accretions on aircraft surfaces can drastically impair aerodynamic performances and control authority. In order to investigate icing effects on the aerodynamic characteristics of KC-100 aircraft, a state-of-the-art CFD code, FENSAP-ICE, was used. A main wing section and full configuration of KC-100 aircraft were considered for the icing analysis. Also, shapes of iced area were calculated for the design of anti-/de-icing devices. The iced areas around leading edge of main wing and horizontal tail wing were observed maximum 7.07% and 11.2% of the chord length of wing section, respectively. In case of wind shield, 16.7% of its area turned out to be covered by ice. The lift of KC-100 aircraft were decreased to 64.3%, while the drag was increased to 55.2%.

A Study of Droplets and Icing Characteristics on Injector in a Liquid Phase LPG Injection Engine (액상분사식 LPG엔진 인젝터의 후적 및 아이싱 특성에 관한 연구)

  • Kim, Chang-Up;Choi, Kyo-Nam;Kang, Kern-Yong;Park, Cheol-Woong
    • Journal of ILASS-Korea
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    • v.12 no.1
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    • pp.38-44
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    • 2007
  • Since the Liquid Phase LPG injection (LPLI) system has Advantages in power generation and emission characteristics compared to the mixer-type fuel-supply system, a variety of studies regarding LPLi system has been conducted and its applications are made in automobile industry. However, the heat extraction due to the evaporation of liquid fuel, causes not only a post-accumulation of fuel but also an icing phenomenon which is a frost of moisture in the air around the nozzle tip. Since there exists a difficulty in the accurate control of air fuel ratio in both fuel supply systems, it can result in poor engine performance and a large amount of harmful emissions. This research examines the characteristics of icing phenomenon and develops anti-icing bushing to prevent an icing on the surface of the injection tip. It was found that n-butane, which has a relatively high boiling point ($-0.5^{\circ}C$), was a main species of post-accumulation. Also the results show that the post-accumulation problem was allevaited the utilization of a large inner to outer bore ratio and smooth surface roughness. In addition, an icing phenomenon and its formation process were found to be mainly affected by the humidity and the temperature of inlet air in an inlet duct. Also, it was observed that an icing phenomenon is lessened using aluminum bushing whose end coincides with the end of fuel injection tip in length.

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Droplet anti icing visualization research through hydrophobic variation of surface structure (소수성 표면의 형상 변화를 통한 액적의 방빙 가시화 연구)

  • Jinwook Choi;Wang Tao;Seolha Kim
    • Journal of the Korean Society of Visualization
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    • v.21 no.3
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    • pp.7-14
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    • 2023
  • In this study, we investigated the freezing delay time on surfaces with different patterns under -30° conditions through visualization experiments. Among various pattern structures, we fabricated the shape and surface of liquid from the spacing using circular filaments and hole structures. Additionally, using a high-speed camera, we visualized the freezing scenes, enabling us to obtain freezing images and measure the freezing time of the liquid. For each structure, the contact angle and solid fraction of the surface varied. We observed that the freezing delay time was longest when the contact angle was largest and the solid fraction was smallest within the experimental results. We analyzed the variation in anti-icing time using the heat exchange equation between the patterned surface and the liquid.

Bioinspired Nanoengineering of Multifunctional Superhydrophobic Surfaces

  • Choi, Chang-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.102-133
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    • 2015
  • Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

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A Study on the Anti-lcing Performance Evaluation and Design Guide for Weather-Tight Door of the Vessels Operating in Cold Region (빙해선박 풍우밀문의 결빙방지 성능평가 및 설계기준에 관한 연구)

  • Seo, Young-Kyo;Jung, Young-Jun
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.6
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    • pp.450-457
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    • 2013
  • For the design guide of a vessel operating in cold region, numerical analysis was carried out to evaluate the weather-tight door which installed the heating cables by using ANSYS 13.0 Transient Thermal. The numerical analysis was performed by considering Advection-Diffusion equation. This study based on the experimental results of 'A study on Anti-Icing Technique for Weather-Tight Door of Ice-Strengthened Vessels'(Jeong, et al., 2011a) in KIOST. For validation of the numerical analysis results, the cold chamber experimental data measured by the heat sensors in certain location of the weather-tight door was used. The external environmental temperature which varies from $5^{\circ}C$ to $-55^{\circ}C$ was considered in numerical analysis. Also three different heating cables which have the heat capacity of 33W/m, 45W/m and 66W/m were adapted for the design parameters to be the most efficient and guidelines for anti-icing design of the weather tight door.