• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.83-90
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• 2001

Cooling garments are being considered for reducing heat strain in hot environment. We evaluated the effectiveness of ice gel-based cooling vest in hot environment both resting and exercising. Four male subjects were exposed to heat(4$0^{\circ}C$, 50%RH) with vest or without it. The results were as follows; In case of the trial wearing ice gel-based cooling vest, total body weight loss, and local sweat volume were less than those without it. Mean skin temperature, rectal temperature, pulse, energy expenditure, temperature of inside clothes, and humidity of inside also were lower than those without cooling vest. By subjective thermal sensation, subjective humidity sensation, and thermal comfort sensation, it was proved that non-wearing vest decreased comfort than wearing that. These results suggested that wearing ice gel-based cooling vest reduced human heat strain in hot environment both resting and exercising.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.65-70
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• 2006

This study is to experimentally evaluate the cooling performance of the Bonding type and Injection type of heat sink using three different kinds of industrial Peltier module by digital LabViewTM measurement. Injection type of heat sink could be more efficient for the heat transfer than Bonding type, even with 30% more radiating surface area. In addition, the experimental results revealed that the sufficient power supplied was able to show the better cooling performance of Peltier module. In order to verify the optimal cooling performance of the cooling device, two Peltier module, HMN 6040 and HMN 1550 with Bonding and Injection type of heat sink were used. The cooling performance with injection type of heat sink was 2.11% and 6.24% better than that with bonding type of heat sink under the HMN 6040 and HMN 1550, respectively.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1168-1173
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• 2006

This research is to verify the cooling effect of the acting surface on the rotary motor using heat pipe and conventional cooling fan. In order to show the cooling performance of the rotary motor and heat pipe with the fin-typed heat sink, the surface temperature of the motor and condenser was measured in real time. The experiments were also conducted as for not only cooling device installed with heat pipe only, but with heat pipe and conventional cooling fan simultaneously.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.31-36
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• 2015

The demand for multi-functionality, high density, high performance, and miniaturization of IC devices has caused the technology paradigm shift for electronic packaging. So, thermal management of new packaged chips becomes a bottleneck for the performance of next generation devices. Among various thermal solutions such as heat sink, heat spreader, TIM, thermoelectric cooler, etc. on-chip liquid cooling module was investigated in this study. Micro-channel was fabricated on Si wafer using a deep reactive ion etching, and 3 different micro-channel designs (straight MC, serpentine MC, zigzag MC) were formed to evalute the effectiveness of liquid cooling. At the heating temperature of $200^{\circ}C$ and coolant flow rate of 150ml/min, straight MC showed the high temperature differential of ${\sim}44^{\circ}C$ after liquid cooling. The shape of liquid flowing through micro-channel was observed by fluorescence microscope, and the temperarue differential of liquid cooling module was measuremd by IR microscope.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.323-331
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• 2012

Since the 1970s, the mechanical properties of concrete at high temperature, such as compressive strength, elastic modulus, thermal strain, etc. have been investigated. Internal and external factors should be effect to concrete elevated temperature. In particular, the thermal properties of aggregate and cooling conditions are most important to estimate residual mechanical properties. This study evaluates the mechanical properties of concrete with aggregate type and cooling methods. We use normal and light aggregate for different thermal properties, and also test mechanical properties to use ${\O}100{\times}200$ mm cylinder specimen according to target temperature, slow cooling and water cooling. We found that normal aggregate concrete that uses is more highly influenced by cooling conditions than concrete that uses light aggregate concrete. In addition, the residual mechanical properties of concrete increase as cooling velocity lowers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.169-174
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• 2006

This paper is related to a design of high pressure sub-scale combustor with regenerative reeling. As a previous step for the evaluation of thermal heat flux, a similar combustor with cooling water was manufactured. Design conditions with high combustion efficiency and cooling performance were verified through the hot firing tests of the water-cooled high pressure combustor. Finally the regeneratively cooled high pressure combustor has been designed based on these data. After manufacturing it, its practical utility will be tested and verified through hot firing tests.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.197-204
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• 2004

A design of regenerative cooling system of 30 ton level thrust combustion chamber for ground test has been performed. The 1-D design code has been validated by comparing with the heat flux of the NAL calorimeter for high chamber pressure and water-cooling performance of the ECC engine of MOBIS. The present design code has been confirmed to predict accurately the heat flux and water-cooling performance for high chamber pressure condition. The maximum hot-gas-side wall temperature is predicted to be about 720 K without thermal barrier coating and the coolant-side wall temperature is less than the coking temperature of RP-1. The coolant temperature rises nearly 100 K with thermal barrier coating when Jet-A1 is used as coolant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.21-24
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• 2010

The cooling channel of the preburner for staged combustion engines was studied. The combustion pressure of the researched preburner is about 210 bar which is very high compared with the engines of the Korean Launch Vechicle and 30 ton class liquid rocket engines developed as a pre-research program. Also, the combustion is an oxygen rich process unlike the gas generators of open cycle kerosene engines. Thus the cooling process is very important to make the preburner stable. Many configurations for the preburner were developed and numerically analyzed. As a result, the pressure loss could be reached below the target.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.132-136
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• 2004

Experimental study has been conducted to investigate effect of mainstream turbulence intensity on film cooling performance of staggered rows of rectangular holes in combustor. Temperature fields and adiabatic film cooling effectiveness under $10\%$ mainstream turbulence intensity are measured. The results of temperature fields show that overall values are decreased and thicker film of coolant is formed downstream of rows of holes for high mainstream turbulence intensity. The results of film cooling effectiveness show that the values around the holes are smaller than the case of the low mainstream turbulence intensity, however, the difference of film cooing performance is decreasedforthefurtherdownstream.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.61-67
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• 2011

The cooling module needs enough space (or distance) from hood to absorb the energy from any pedestrian collision. Downsized cooling module for pedestrian protection is important to reduce the severity of pedestrian injury. When a vehicle collision happens, the downsized cooling module is required to reduce the risk of injury to the upper legs of adults and the heads of children. In this study, the performance of cooling module to cool the engine was investigated under 25% height reduction. The heat dissipation and pressure drop characteristics have been experimentally studied with the variation of coolant flow rate, air inlet velocity and A/C operation ON/OFF for the downsized cooling module. The results indicated that the cooling performance was about 94% level compared to that of the conventional cooling module. Therefore, we checked that the cooling module had good performance, and expected that the cooling module could meet the same cooling performance as conventional cooling module through optimization of components efficiency.