• Journal of the Korean Applied Science and Technology
• /
• v.38 no.6
• /
• pp.1355-1369
• /
• 2021

This study improved the algorithm for the road ice prediction algorithm and analyzed the prediction rate when comparing actual field measurement data and algorithm prediction value. For analysis, road and weather conditions were measured in Geumdong-ri, Sinbuk-myeon, Pocheon-si. First algorithm selected previous research result algorithm. And the 4th algorithm was improved according to the actual freezing conditions and measured values. Finally, five algorithms were developed: freezing by condensation, freezing by precipitation, freezing by snow, continuous freezing, and freezing by wind speed. When forecasting using an algorithm at the Pocheon site, the freezing hit rate was improved to 93.2%. When calculating the combination ratio for the algorithm. the algorithm for freezing due to condensation and the continuation of the frozen state accounted for 95.7%.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.6
• /
• pp.1507-1516
• /
• 2020

This study analyzed the scenario for road freezing section by applying the road freezing evaluation algorithm. To apply road freezing algorithm, the influencing factors on road freezing were reviewed. Observation data from four points, Mokgam IC, Jeongneung tunnel, Seongsan bridge, and Yeomchang bridge were used for analysis. All observatories are installed on the expressway, and they are classified for the analysis of road freezing characteristics. When the difference between the road surface temperature and dew-point temperature of the road freezing evaluation algorithm was 3℃ or less, the section where road freezing occurred was checked. In addition, road freezing evaluation was derived through the change of the road surface condition and water film thickness of the freezing section.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.358-361
• /
• 2007

Most aircraft cruise in the stratosphere at which temperature is below $-50^{\circ}C$ md, as a result, the surface of aircraft can be iced up. Ice on the wing can change aerodynamic characteristic and results in the deterioration of its performance. Ice on the engine inlet increases the possibility of compressor blade damage and affects the performance and safety of the engine. This paper focused on the development of icing simulation device for analyzing effect of icing on engine performance. Icing simulation tests were conducted with a liquid air system and a icing simulation device and results show that icing could be simulated with this system.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.6
• /
• pp.526-532
• /
• 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 $0.5g/m^3$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.390-391
• /
• 2012

동절기 혹한으로 인해 내륙 수로가 결빙될 경우 수로 운항이 상당 기간 불가능해짐에 따라 경제적 손실이 발생하게 된다. 연안 해운이 주로 발달한 우리나라의 경우 동절기 결빙에 따른 선박 운항 장애에 관한 사례가 많지 않지만, 내륙 수로 운항의 비중이 높고 혹한기가 긴 북유럽과 미국 북부지역에서는 수로 결빙의 메카니즘 및 대처 방안에 대한 연구가 많이 이루어져 왔다. 본 논문에서는 지금까지 밝혀진 주요한 수로 결빙 메카니즘 및 해결 방안에 대하여 소개하였다.

• Aerospace Engineering and Technology
• /
• v.7 no.2
• /
• pp.196-204
• /
• 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).

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.6
• /
• pp.530-536
• /
• 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%.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.11
• /
• pp.1105-1114
• /
• 2010

Ice shapes accumulated on the aircraft surfaces are categorized into rime and glaze ice, which are highly dependent on various parameters such as ambient temperature, liquid water contents (LWC), mean volumetric droplet diameter and freestream velocity. In this study, quantitative analyses on the ice accretion have been attempted in a systematical manner and the key findings are as follows. First, the increase of freestream velocity can cause tremendous change in the ice accumulation such as the growth of ice accretion area, ice heading direction and maximum thickness of ice horn. Second, LWC is found to be linearly proportional to the ice accretion area. Third, the effects of ambient temperature on incoming water mass seem to be relatively small in comparison with LWC and freestream velocity. Finally, it was shown that MVD has only a little influence on ice shapes. However, it may increase the ice accretion area by increasing the droplet impacting range.

• Journal of Satellite, Information and Communications
• /
• v.9 no.3
• /
• pp.104-108
• /
• 2014

This paper represents the effect analysis results of surface-Icing on the UHF-band antenna for Space Launch Vehicle. In order to obtain structural model of the surface-icing, Relative Permittivity of ice at $-180^{\circ}C$ was extracted. Using this surface-Icing model, UHF-band antenna simulation and comparative analysis about the antenna parameters such as resonance frequency, reflection loss and radiation pattern were performed for each case of with or without surface-icing. Simulation results show that resonance frequency is shifted out of operation frequency due to the additional ice permittivity. This resonance frequency changes cause severe affect to the antenna performance and its radiation pattern.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.40 no.8
• /
• pp.495-501
• /
• 2016

The measurement of icing conditions needs to be carried out accurately by the ice detector system of an aircraft. Ice detector systems should be installed in locations not affected by backwash, rotor downwash or moving doors or other equipment. Various analyses were carried out in order to find the proper locations sufficiently far from these interfering effects. In this study, the optimum position of the ice detector was assessed using computer simulation, with respect to different flight modes, flow velocities and the amount and distribution of liquid water around the sensor.