• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.541-549
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• 2012

The study adopted a freezing prevention method of the upper deck which used heating coil, and carried out numerical analysis by using ANSYS 13.0 CFD for design guide of the vessel operating in cold region. It is based on the experimental results of the anti-icing performance tests which were carried at cold room chamber in MOERI. Numerical analysis for the design guide was performed by considering S.S.T. (Shear Stress Transport) turbulent model for flow separation effects and the turbulence which occurred in interfaces of the numerical model in order to express appropriate heat transmission phenomenon. The numerical result shows average temperature of the upper deck surface appeared similarly compared with the indoor chamber test. The design guide for optimum freezing prevention presented through heat transmission capability and interval of the heat coil in various outdoor temperature($10^{\circ}C{\sim}-30^{\circ}C$) and wind speed(1m/s~7m/s).

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.541-549
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• 2022

This study investigates anti-icing design by conjugate heat transfer analysis in lab-scale printed circuit heat exchanger (PCHE) for supply of cryogenic high pressure liquid hydrogen. The conjugate heat transfer analysis by using computational dynamics (CFD) provided various temperature distributions at important locations in PCHE heat exchanger and predicted the possibility of freezing in hot channel. And, the effect of inlet temperature of glycol water was analyzed in order to resolve the freezing problem in PCHE.

• Journal of the Korean Geosynthetics Society
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• v.11 no.3
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• pp.27-35
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• 2012

In this paper, the frost heaving and thawing characteristics of flexible pavement structure were evaluated in the large scale freezer which have a specification of temperature range $-20^{\circ}C{\sim}10^{\circ}C$ and $3.2m(L){\times}3.2m(B){\times}2.4m(H)$ in size. The insulated steel box with the size of $0.9m(L){\times}0.9m(B){\times}0.9m(H)$ was used to simulate actual pavement road structure. The variation of temperature, frost heave amount and frost heave pressure were measured through the instrument of TDS-602 data logger. LFWD (light falling weight deflectometer) was used to determine the change of deflection due to the frost heaving and thawing. Furthermore, the influence of aggregate layer to the freezing of the subgrade soil was studied to verify the function and effectiveness of the anti-freezing layer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.433-439
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• 2011

The frost depth(frost penetration) is used to install anti-frost heave layers in pavement designs. The freezing index is calculated by an annual accumulated value of multiplying the period of time with temperatures below zero, and the corresponding temperature. Therefore, the DAAT(daily average air temperature) calculation method may play an effect on the FI(freezing index). The Weather Observatory used to supply 4 average air temperatures per day, but currently supplies 8 per day. With this study, we divided the southern part(below FI=$350^{\circ}C{\cdot}day$) of the Korean peninsula into 6 areas according to site conditions(low embankment, embankment-cutting slope, and the cutting slope) and established a field measurement system for 15 positions to check the effects on the result of FI according to differing DAAT calculation methods. The air temperatures obtained by the field measurement system was used to calculate and compare the FI. As a result, the freezing index calculated based on the $DAAT_4(T_4)$ is normally greater by 3% than the one on $DAAT_8(T_8)$. In addition, the calibration equation for the freezing index using air temperatures was proposed through the research.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.15-16
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• 2022

In order to examine the adhesion characteristics of road pavement according to environmental conditions, the freezing time of cement mortar and the adhesion performance between ice and pavement were evaluated depending on the presence or absence of polymer and water repellent. As a result of measuring the ice formation time, it was found that there was no delay when a polymer was added, but the complete freezing time was delayed when a water repellent was added. As a result of measuring the strength of ice adhesion, it was found that the bonding force between ice and the surface of the test body was greatly generated in the test body without water repellent. In the case of a test specimen to which a water repellent was added, it was found that the bonding strength between the test specimen surface and ice was reduced.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.231-236
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• 2001

In this paper, tests are carried out in order to investigate the validities of anti-freeze agent, which is developed using waste coolant and existing anti-freeze agent through previous study, under various W/C and contents. According to test results, adequate dosage of developed anti-freeze agent shows positive performance in slump, air content and chloride contents in the mixture of 40% and 50% of W/C, accelerates setting time and drops the freezing temperature of concrete. Meanwhile, in the region of 30% of W/C, followings can be indicated that increasing the contents of anti-freeze agent leads to reduce fluidity, rapid setting and excessive chloride contents. Improved strength gain is shown when anti-freeze agent is used with in 8%.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.116-124
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• 1996

The purpose of The work described in this paper is to clear up the initial moisture content, specific surface, air drying and freezing-thawing process on liquid limit of clayey soils distributed widely at estuary of three main rivers in the west coast. To this end, a series of tests were conducted on clayey soils samples with natural state and treated state. From the test results, the liquid limit was decreased with decrement of initial moisture content, air drying process, and freezing-thawing cycles and increased with increment of specific surface. The specific surface which influenced on the liquid limit is over $25 m^2$m$^2$/g, and their relationships are well formulated. Air drying process is expected to improve the engineering properties of the soils such the pro-water properties were changed to anti-water proper-ties through lowering of water holding as resulted to incline from A-7-5 to A-5 on the soil classificaction plastic chart. The freezing-thawing process decreased 20% of liquid limit, especially under the first cycle of the behavious, as a result of above mentioned reasons, phase change of soil-water system brought the decrement of specific surface and affected to the liquid limit.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.149-158
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• 2007

Evaluation of the asphalt mixture modified with crumb rubber modifier(CRM) was performed to estimate possibility of using it as a paying material. OACs(optimum asphalt content) of CRM modified asphalt mixtures by dry process and wet process were determined by Marshall mix design and Wheel tracking test and moisture susceptibility test by freezing and thawing were carried out with CRM modified asphalt mixtures at OACs. The results from these tests, resistance of permanent deformation of CRM modified asphalt mixtures were superior to one of AP-5 while showing very low resistance of moisture sensitivity by freezing and thawing. This means that CRM modified asphalt mixtures are very sensitive to freezing and thawing. However, CRM modified asphalt mixture with anti-stripping material showed high improvement to resistance of moisture susceptibility by freezing and thawing. Therefore, it is recommended that when CRM mixtures were used in domestic, CRM modified asphalt mixtures should be with prevention against freezing and thawing resistance by moisture susceptibility.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.279-280
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• 2005