• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.245-247
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• 2001

In this paper, the temperature distribution and thermal stress analysis of 50kVA pole mold transformer for power distribution are investigated by FEM program. The temperature rise test of designed mold transformer is carried out and test result is analyzed compare to simulation data.

• 산업기술연구
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• 제31권A호
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• pp.21-25
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• 2011

A comparison of temperature distributions along the fin length coordinate between two different fin tip boundary conditions for a circular pin fin is made by using the one-dimensional analytic method. One tip boundary condition is the actual fin tip boundary condition and fin tip temperature is arbitrarily given for another fin tip boundary condition. The value of the fin base temperature is depend on the fin base thickness and fin radius. One of the results shows that the temperature distribution along the fin length coordinate for the actual fin tip boundary condition and that for the arbitrarily given fin tip temperature are the same if the arbitrarily given fin tip temperature and the fin tip temperature for the actual fin tip boundary condition are the same.

• Journal of Mechanical Science and Technology
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• 제18권5호
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• pp.820-829
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• 2004

The In-Containment Refueling Water Storage Tank (IRWST), one of the design improvements applied to the APR -1400, has a function to condense the high enthalpy fluid discharged from the Reactor Coolant System (RCS). The condensation of discharged fluid by the tank water drives the tank temperature high and causes oscillatory condensation. Also if the tank cooling water temperature approaches the saturated state, the steam bubble may escape from the water uncondensed. These oscillatory condensation and bubble escape would burden the undue load to the tank structure, pressurize the tank, and degrade its intended function. For these reasons simple analytical modeling and experimental works were performed in order to predict exact tank temperature distribution and to find the effective cooling method to keep the tank temperature below the bubble escape limit (93.3$^{\circ}C$), which was experimentally proven by other researchers. Both the analytical model and experimental results show that the temperature distributions are horizontally stratified. Particularly, the hot liquid produced by the condensation around the sparger holes goes up straight like a thermal plume. Also, the momentum of the discharged fluid is not so strong to interrupt this horizontal thermal stratification significantly. Therefore the layout and shape of sparger is not so important as long as the location of the sparger hole is sufficiently close to the bottom of the tank. Finally, for the effective tank cooling it is recommended that the locations of the discharge and intake lines of the cooling system be cautiously selected considering the temperature distribution, the water level change, and the cooling effectiveness.

• 대한설비공학회지:설비저널
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• 제13권2호
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• pp.10-15
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• 1984

The aims of this study are to obtain a suitable method and a proper mesh for investigation of the temperature distribution and heat transfer. The relative errors of temperature distribution and heat transfer for each mesh are acquired in accordance with linear finite element (FEM 3), square finite element (FEM 6), cubic finite element (FEM 10), and finite difference method (FDM). It has been found that FEM 10 is the most accurate measure to obtain the temperature distribution and heat transfer. However, no significant results have been obtained successfully, because when higher order finite element methods are used the more computational efforts are necessary due to the distribution of elements. The results of this study are as follows ; 1 . In case of a=b=L, meshes for less than $1\%$ relative errors (temperature distribution) acquired in various methods to exact solution are $2\times2,\;4\times4,\;8\times8\;and\;8\tiems8$ for each FEM 10, FEM 6, FEM 3 and FDM and a=L, b=1/2L are $10\times5$ for each FEM 3 and FDM. And the tendency of results acquired of heat transfer is similar to those above. 2 . In computational efforts (a=b=L), FEM 6 has taken 21 times. and FEM 10 154times FEM 3 and FDM and FEM 3 is the sane as FDM.

• 한국수산과학회지
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• 제55권5호
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• pp.670-680
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• 2022

Owing to the lack of a cold-chain distribution system, most seafood is generally distributed under room temperature conditions. However the degradation of freshness during the distribution process can lead to disputes between sellers and consumers. The most widely used method for low-temperature distribution for seafood includes packaging it with styrofoam boxes and cold packs. In this study, vacuum-packed frozen fillets of four fish species of [white meat (Paralichthys olivaceus and Sebastes schlegelii) and red meat (Scomber japonicus and Scomberomorus niphonius)] were placed in styrofoam boxes with cold packs. Thereafter, changes in chemical (including pH, volatile basic nitrogen, and trimethylamine), physical (odor intensity, hardness, and chewiness), and microbial (viable cell count) characteristics of the fillets were measured during storage at 25℃. To identify the suitable method of determining freshness during the room-temperature distribution, several factors were considered, which included significant difference verification, correlation coefficients, and economic efficiency (experimental cost and time). Volatile basic nitrogen, pH, odor intensity, and viable cell count are the most rapid and accurate freshness indicators for determining freshness of frozen fish fillets during.

• 동력기계공학회지
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• 제12권2호
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• pp.5-11
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• 2008

An analytical study was performed to have temperature and thermal stress distribution on a piston with the change of the 2nd land length of a piston and the existence of knocking in a cylinder. The result showed that the temperature on the skirt region was about $4\sim10^{\circ}C$ higher than that on the pin region. However the thermal stress on the skirt region was about 4MPa lower than on the pin region. It may be due to the higher heat release rate on the pin boss than on the skirt. The result regarding the variation of the 2nd land length of the piston showed that the temperature distribution on the piston was getting lower and the thermal stress distribution was getting higher as the 2nd land length of the piston was shorter.

• International Journal of Contents
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• 제5권2호
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• pp.16-19
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• 2009

In this paper, we concern about the distribution characteristics of surface temperature by the increment of time, diffusivity and heat flux on irradiating of a laser. The penetration depth corresponding to the induced constant heat flux or irradiated laser, is simulated by a computer algorithm. The distribution of temperature versus penetration depth for the variation of time and diffusivity is characterized at the constant heat flux and on irradiating of a laser. The temperature of constant heat flux at the fixed diffusivity or time, is decreased by the pattern of exponential function as the time t or diffusivity a is increased (a=10, 100, 1000). The temperature of constant heat flux is not changed but exponentially fixed with the increasing diffusivity and the fixed time. On the other hand, the temperature of laser at the fixed diffusivity or time is decreased linearly. Our results show that the characteristics of the simulated surface temperature in a semi-infinite solid are similar to the graphs on theoretical consideration.

• 한국전산유체공학회지
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• 제5권3호
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• pp.8-15
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• 2000

This research is aimed to find out how the inlet angle of secondary air affects the uniformity of temperature distribution inside a small incinerator. A commercial code, PHOENICS, is used to simulate the thermal-flow field of an incinerator. The computational grid system is constructed by Multi-Block technique provided by PHOENICS. Numerical experiments are done with the five different angles of secondary air inlet. The uniformity of temperature distribution is evaluated by checking the standard deviation of temperature distribution in an incinerator. The computational results show that there is the minimum value of standard deviation at the certain angle of secondary air inlet, which means that there is an optimum angle of secondary air inlet that could improve the uniformity of temperature distribution in an incinerator. The optimum angle of secondary air inlet is between 30 degree and 45 degree in this particular case.

• 설비공학논문집
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• 제20권7호
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• pp.478-485
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• 2008

The extreme steam temperature deviation experienced in the superheater of a tangentially fired boiler can seriously affect its economic and safe operation. This temperature deviation is one of the main causes of boiler tube failures. The steam temperature deviation is mainly due to the thermal load deviation in the lateral direction of the superheater. The thermal load deviation consists of several causes. One of the causes is the non-uniform heat flow distribution of burnt gas on the superheater tube system. This distribution is very difficult to measure in situ using direct experimental techniques. So, we need thermal load model to estimate the tube temperature. In this paper, we propose a thermal load distribution model by using CFD analysis and plant data. We successfully predict the tube temperature and the steam flow rate in a final superheater system from the thermal load model and one dimensional heat-flow system analysis. The proposed model and analysis method would be valuable in preventing the frequent tube failure of the final superheater tubes.

• 한국재료학회지
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• 제5권2호
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• pp.232-238
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• 1995

The thermal stress distribution of WC and Ni binder phases In WC-26st.%Ni and WC-6wt.%Ni composites has been investigated over the temperature range 100-900 K using a time-of-flight neutron diffractometer. To determine the stress distribution, the breadths of WC and Ni peaks in the reference powder and the composites were analyzed. The peak breadths were corrected for particle size effect using a procedure based on the integral peak breadth method of particle size-strain analysis. The result shows a broad range of strain, and thus stress, is present in the WC and Ni binder phases of the composites. The strain distribution of both phases broadens as the temperature decreases, and some fraction of total strain distribution of the WC phase remains tensile regardless of the temperature. The strain distribution of the WC phase broadens as the binder content increases, and that of Ni binder phase broadens as the binder content decreases, which means the strain distribution broadens as the absolute value of residual stress increase.