• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.411-418
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• 1989

Quenching effect depends upon coolingability of quenchant as well as the composition of steel. Study on the coolingability of quenchants is important in cooling process and heat treatment of steel. Experimental apparatus and measuring method follow Korean Industrial Standard. Distilled water, different concentration of NaCl, NaOH and Na$_{2}$CO$_{3}$ solutions were compared. Also the effect of temperature of distilled water were calculated. Experimental results were examined with F.E.M. analysis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.419-423
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• 1989

The laboratory quench method used in this study is based on plunging a silver cylinder heated to 800.deg. C in to mineral oil and vegetable at given temperature. Experimental apparatus and measuring method followed Korean Industrial Standard. Colling curves at the boundary of the cylinder measured by a silver-alumel thermocouple is recorded throughout the quenching period. Using the cooling curves, the coolingability of the quenching oils at various temperatures were compared and discussed.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.16-22
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• 2012

Performance of a liquid rocket thrust chamber with regenerative cooling scheme has been numerically analyzed using in-house CFD code which can predict combustion/cooling performance and provide nozzle design parameters. This paper investigates trade-offs between combustion and cooling performance with varying amount of fuel directly injected into the chamber wall to form cooling films and mixture ratios for the peripheral injectors. Further efforts to verify/improve the simulation methodology including comparison with the firing test results are planned to make it a reliable tool to optimize the film cooling and other major design parameters.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.35-41
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• 2012

Performance of a liquid rocket thrust chamber with regenerative cooling scheme has been numerically analyzed using in-house CFD code which can predict combustion/cooling performance and provide nozzle design parameters. This paper investigates trade-offs between combustion and cooling performance with varying amount of fuel directly injected into the chamber wall to form cooling films. Also is analyzed the effect of varying mixture ratios for the peripheral injectors on combustion performance enhancement. Further efforts to verify/improve the simulation methodology including comparison with the firing test results are planned to make it a reliable tool to optimize the film cooling and other major design parameters.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.215-218
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• 2005

An optimal fuel manifold is suggested to improve the cooling performance of injector face plate. The cooling performance at the center area of the injector face plate is to be augmented while the spatial injection uniformity is maintained. The comparison of the cooling performance of 7 candidates gives the conclusion that the dividing plate from 2-3 injector row to 9-10 injector row is an optimal. The maximum face plate temperature decreases by $27\%$ while the injection uniformity is close to that of the original design. The pressure drop in the fuel manifold of the optimal design is also same as the original design.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.92-100
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• 2005

An optimal fuel manifold is suggested to improve the cooling performance of an injector face plate. The cooling performance at the center area of the injector face plate is to be augmented while the spatial injection uniformity is maintained. The comparison of the cooling performance of f candidates gives the conclusion that the dividing plate from 2-3 injector .ow to 9-10 injector. row is an optimal. The maximum face plate temperature decreases by 27$\%$ while the injection uniformity is close to that of the original design. The pressure drop in the fuel manifold of the optimal design is also same as the original design.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.988-991
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• 2011

This study aims to analyze the effects of design parameters of the slotted cooling liner for air-breathing propulsion system. The three kinds of design parameters of the slotted cooling liner were selected and were investigated effect on the cooling performance of the slotted cooling liner. In this paper calculation results for inner wall temperature of cooling liner from heat transfer calculations were presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.478-483
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• 2017

This paper investigated experimentally the performance of cooling systems using thermoelectric and piezoelectric modules for local heating and temperature control, such as a handheld electronic devices. The temperature distribution of the cooling region using thermoelectric modules was measured when the piezoelectric module was and was not with a frequency of 80Hz and 110Hz. The coefficients of performance were also calculated by the temperature results, and the thermo-flow phenomena in the cold region was visualized under the same conditions. The results of the temperature distribution measurements and the coefficient of performance showed that the cooling performance of the cooling system using thermoelectric modules can be improved by operating the piezoelectric module. In addition, when the piezoelectric module was operated based on the result of visualization in the cold region, which was formed by thermoelectric modules, the performance thermoelectric cooling was improved by the thermo-flow formed in the entire cold region as the forced convection of vibration was generated on the local cold region by the piezoelectric module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.110-115
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• 2009

Recently, there has been a growing global interest in environmental conservation, and the field of electric power equipment has been working to become more environment-friendly. Accordingly, the low noise cooling fan of power transformers was developed through the improvement of blade shape. These are expected to apply to existing power transformers and low noise transformers. It is essential for low noise fan to possess good cooling performance as well as low audible noises. But, there was not analysis on the audible noise level and the cooling performance for low noise cooling fans until present. In this paper, we measure the audible noise level and the flow rate of low noise cooling fans to inspect the performance, Also, we confirmed that the low noise cooling fan is available to apply to power transformers through temperature rise tests of power transformers.

• Journal of the Microelectronics and Packaging Society
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• v.5 no.2
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• pp.27-36
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• 1998

통신시스템의 고발열 전자부품 냉각을 위해 3종류의 써모싸이폰을 각각의 용도에 따라 개 발하였으며 그 각각의 설계변수에 대한 냉각특성을 실험적으로 구하였다. TS-I에서는 증발부 내부 에 금속스크린 메쉬형심지를 삽입함으로써 시간에 따른 온도 변화를 작게 하여 냉각성능 안정성을 확보하였고, TS-II에서는 9W/cm2의 높은 냉각성능을 가진 루프형 써모사이폰을 개발하였으며 TS-III에서는 작동유체의 종류, 파이프개수 와이어 삽입여부등 써모사이폰의 주요 설계변수에 따 른 냉각특성을 구하였다.