• 소성∙가공
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• 제15권1호
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• pp.15-20
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• 2006

The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filling difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation for both the conventional molding and the RTR molding processes.

• 한국에너지공학회:학술대회논문집
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• 한국태양에너지학회, 한국에너지공학회 1993년도 춘계 공동학술발표회 초록집
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• pp.64-69
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• 1993

The solar energy collection of a passive solar system depends on the finish of collecting surfaces. In this study, the test models of T.W system with different wall surface finishes were constructed, and the temperature distribution through the models was monitored. At the same time, a computer program based on F.D.M was developed in order to simulate various surface finishes. The difference of indoor temperature between the model with white color finish ($\alpha$=0.25) and the one with black color finish ($\alpha$=0.95) was about 1$0^{\circ}C$. For the wall with selective coating, the indoor temperature was 4-5$^{\circ}C$ higher than that of red brick wall, and 3-4$^{\circ}C$ higher than that of wall with black paint.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.41-54
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• 1995

A mathematical model for wall-flow monolith ceramic diesel particulate filter was developed in order to describe the processes which take place in the filter during regeneration. The major output of the model comprises ceramic wall temperature and regeneration time(soot reduction). Various numerical tests were performed to demonstrate how the gas oxygen concentration, flow rate and the initial particulate trap loading affect the regeneration time and peak trap temperature. The model is shown to b in reasonable agreement with the published experimental results. This model can be applied to predict the thermal shock failure due to high temperature during combustion regeneration process.

• 설비공학논문집
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• 제10권5호
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• pp.523-534
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• 1998

The convection heat transfer on horizontal circular tube is studied as a conjugated heat transfer problem. With uniform heat generation in a cylindrical heater placed in a cross flow boundary condition, heat flow that is conducted along the wall of the heater creates a non-isothermal surface temperature and non-uniform heat flux distribution. In the present investigation, the effects of circumferential wall heat conduction on convection heat transfer are investigated for the case of forced convection around horizontal circular tube in cross flow of air and water. Non-dimensional conjugation parameter $ K^*$ which can be deduced from the governing energy differential equation should be used to express the effect of circumferential wall heat conduction. Two-dimensional temperature distribution$ T({\gamma,\theta})$ is presented. The influence of circumferential wall heat conduction is demonstrated on graph of local Nusselt number.

• 태양에너지
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• 제12권2호
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• pp.28-42
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• 1992

This investigation is carried out numerically for the two dimensional natural convection and surface radiation heat transfer in a square enclosure. The bottom wall is a constant heat flux at hot temperature and also top wall is isothermal at cold temperature whereas the left and right side walls are adiabatic except a transparent window on the right side partially. The exchange of radiant energy is obtained by the net radiation method and the shape factor by the crossed string method. The change in temperature and Nusselt number distributions of the walls due to the effect of the wall emissivity for various emissivities and for various dimensionless insolation energies are investigated. The dimensionless local convective heat flux and local radiative heat flux distributions in the wall except an adiabatic wall are also compared.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
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• pp.9-12
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• 2005

The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filing difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation fur both the conventional molding and the RTR molding processes

• 한국지열·수열에너지학회논문집
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• 제9권4호
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• pp.15-24
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• 2013

On this Thesis, We conduct a research of curtain wall high-rise apartment located in Songdo for preparing a simple method to check possibility of condensation on each part of curtain wall using only indoor temperature, humidity and outdoor temperature. According to CFD analysis result, condensation occurred if indoor environment did not ventilated. On the other hand, in case of ventilation on indoor environment, condensation did not appear; so I could find ventilation prevent surface condensation on inside surface of curtain wall. Moreover, when temperature of the floor is higher, condensation is decrease more than lower floor temperature.

• 대한기계학회논문집
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• 제18권11호
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• pp.3057-3065
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• 1994

An experimental study has been made for heat transfer and particle deposition during the Modified Chemical Vapor Deposition process which is currently utilized to manufacture high quality optical waveguides. The distributions of tube wall temperatures, rates and efficiencies of particle deposition were measured. Results indicate that the temperature distributions of the tube wall in the axial direction yield the quasi-steady form in which temperature distributions fit in one curve if the relative distance from the moving torch is used as an axial coordinate. Due to the repeated heatings from the traversing torch, the wall temperatures are shown to reach the minimum ahead of torch and it is shown that the two torch formulation suggested by Park and Choi is valid to predict this minimum temperature. Measured wall temperatures, particle deposition efficiencies and tapered entry length are compared with the previous modelling results and shown to be in agreement.

• Journal of Advanced Marine Engineering and Technology
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• 제28권7호
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• pp.1055-1062
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• 2004

As for the Production of internal combustion engines there has been further movement toward development of high Performance engines with improved fuel efficiency as well as a lightweight and a small size. These tendencies help to solve the problems in engines for example, such as thermal load. abnormal combustion and so on. In order to investigate these Problems, a thin film-type probe for measuring instantaneous temperature has been suggested. A method for manufacturing such a probe was established in this study The instantaneous surface temperature of a constant volume combustion chamber was measured by using this probe and the heat flux was obtained through Fourier analysis In order to thoroughly understand the characteristics of combustion. authors measured wall temperature of combustion chamber and calculated heat flux through a cylinder wall while varying the protrusion height of probe. For these Purposes, the instantaneous surface temperature probe was developed. thereby making possible the analysis of instantaneous temperature of wall surface and the detection of unsteady heat flux in the constant volume combustion chamber.

• 한국기계가공학회지
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• 제11권4호
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• pp.1-6
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• 2012

This paper addresses the issue of Renewable Energy for Electricity Storage device is one of the NAS (Sodium-Sulfur) battery will be about the module. For safety reasons, not the actual battery cells using a dummy cell in the module's operating temperature setting to examine the characteristics of the insulation vacuum of the wall temperature and external temperature changes measured over time. Upper and lower boundaries of the wall vacuum insulation characteristics cotton C intervals over time, average $5^{\circ}C$, but the temperature is rising, 4C section with little temperature change did not occur. On the other hand, about $3^{\circ}C$ in section 4D, and it was confirmed that the temperature rises. Wall vacuum insulation characteristics over time to look at the experiments and measurements are described.