• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.4
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• pp.960-970
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• 1990

본 연구에서는 단상 밀폐 사각형 열사이폰 루프에서 가열부는 일정 열유속으 로 가열되고 냉각부는 일정온도로 냉각될 경우에 대해 루프 경사각도, 종횡비, 작동유 체 종류 및 관 직경변화에 대한 유동 및 온도변동 특성과 이에따른 전열성능 및 안정 작동범위를 실험적으로 조사하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.1-9
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• 2012

Applicability of regenerative cooling in 2,500 N-class bipropellant thruster using hydrogen peroxide and kerosene was considered for improvement of performance and application in various missions. Calculation was performed by one dimensional approach using hydrogen peroxide as a coolant. The heat flux of thruster at nozzle throat was estimated at 18 - 20 MW/$m^2$. Designed cooling channel width and height were 2.5 mm and 0.5 mm, respectively. Based on designed cooling channel configuration, flat plate model was manufactured and tested for estimation of pressure drop in cooling channel, and CFD analysis was compared with the test result. The maximum error between CFD analysis and experimental result was approximately 13% and average error was approximately 5%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.801-807
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• 2016

This paper aims to compare and study the cooling performance of a battery system in accordance with the inlet and outlet geometry of the air passage in an EV. The arrangement and the heat source of the battery module were fixed, and the inlet/outlet area and its geometry were varied with the analysis of the cooling performance. The results of this study provide suggestions for the air flow stream line inside of a battery, the velocity field, and the temperature distributions. It was confirmed that the volume flow rate of air should be over $400m^3/h$, in order to satisfy conditions under $50^{\circ}C$, which is the limit condition for stable operation. It was also revealed that the diffuser outlet geometry can improve the cooling performance of battery system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.163-170
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• 2011

Applicability of regenerative cooling in 2,500 N-class bipropellant thruster using hydrogen peroxide and kerosene was considered for improvement performance and application in various missions. Calculation was performed by one dimensional approach using hydrogen peroxide as a coolant. In designed regenerative cooling thruster, heat flux at nozzle throat was estimated at 18 ~ 20 $MW/m^2$. Designed cooling channel width and height were 2.5 mm and 0.5 mm, respectively. Based on designed cooling channel configuration, flat plate model was manufactured and tested for estimation of pressure drop in cooling channel, and CFD analysis was compared with the test result. The maximum error between CFD analysis and experimental result was approximately 13% and average error was approximately 5%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.4
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• pp.67-72
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• 2004

A regenerative cooling system has been designed through empirical 1-D analysis for a liquid rocket engine of 30-ton-level thrust. The hot-gas-side wall temperature from 1-D analysis shows 100K difference compared to 3D CFD analysis. Two variations of design with same cooling performance are suggested for different maximum channel widths i.e., 4mm and 2mm. The coolant pressure drop of the latter design is higher by 20%. The maximum liner temperature is about 700K when TBC and the thermal resistance of carbon deposit are considered. So film cooling is recommended to increase the cooling capacity as the present cooling capacity is insufficient

• 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.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.374-378
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• 1996

피동 원자로용기 냉각계통은 원자로 용기를 둘러싸고 있는 격납공기 외부가 공기에 자연순환에 의해 냉각하는 방식으로 공기 흐름 구동력은 원자로용기의 외부 유로의 공기와 주변 대기와의 밀도 차이에 의하여 피동적으로 형성됨에 따라 높은 작동 신뢰성이 보장된 개념으로서 본 연구에서는 공기입구 위치에 따른 영향 및 격납용기와 유로 벽면간의 복사 효과 까지를 고려 할 수 있도록 해석 모형을 개선 시키고 개선된 모형을 이용하여 계통을 구성하는 설계인자들이 계통의 성능 및 크기에 미치는 영향등을 분석하였다. 이러한 분석을 통하여 공기의 입구 위치가 계통의 열제거용량에 미치는 영향, 상향공기 유로에서의 복사 열전달 고려 유무가 해석 결과에 미치는 영향 그리고 설계인자와 계통 성능간의 상관성을 밝혔다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.161-162
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• 2014

본 연구의 목적은 HVDC Valve module 및 valve tower에 유입되는 냉각 유체의 유동장 동적 해석과 동시에 냉각 유체의 동적 특성을 측정 비교함으로써 유동 해석의 적합성을 판단하고, HVDC valve module과 valve tower의 냉각 유로 및 관련 기구 설계의 기초 자료로 활용하는데 그 목적이 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.69-76
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• 2003

For stable combustion and safety of a structure of the propulsion system, a cooling system to the liquid rocket engine should be incorporated. In this study, Eulerian-Lagrangian scheme for two phase combustion, nongray radiation and soot formation effect, and film-wall interaction have been introduced to study the effect of film cooling. After briefly introducing the governing equation, combustion characteristics with change of wall temperature has been investigated by varying such parameters as fuel mass fraction for film cooling, diameter of the fuel droplet, overall mixture fraction of oxygen to fuel. Also, radiative heat flux is compared with the conductive one at the combustor wall.

• 전기의세계
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• v.28 no.8
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• pp.25-28
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• 1979

일반석유제품에 비해 특이한 사용목적및 특성을 갖는 전기절연유는 유입전기기의 절연및 냉각용으로 장기간에 걸쳐 사용되어 왔다. 최근에 이르러서는 전기기기의 고전압화, 대용량화 추세에 따라 절연유에 대한 요구특성도 더욱 가혹하게 되었으며 이 요구특성을 만족시키기 위하여 부단한 연구와 노력이 뒤따라 현시점에서는 특고압및 초고압 전기기기의 수요에도 대응하게 되었다. 한편, 선진외국에서는 광유계 절연유와는 별도로 합성절연유의 개발이 활발히 진행되고 있는 실정이다. 본란에서는 현재 주종을 이루고 있는 광유계 전기절연유가 갖는 특성및 취급상 유의점을 기술하고저한다.