• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.934-941
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• 2000

We measured the electron transport coefficients, the electron drift velocity W and the longitudinal diffusion coefficient $D_{L}$ in the 0.526% and 5.05% $C_{3}F_{8}$-Ar mixtures over the E/N range from 0.01 Td to 100 Td by the double shutter drift tube, and compared the measured results by Hunter et al. with those. We determined the inelastic collision cross sections for the $C_{3}F_{8}$ molecule by the comparison of the present measurements and the calculation of electron transport coefficients in the $C_{3}F_{8}$-Ar mixtures by using a multi-term Boltzmann equation analysis.

• 한국태양에너지학회 논문집
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• 제21권3호
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• pp.61-68
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• 2001

This study represents numerical analysis on the thermal and fluid flow of the air layer in a solar collector. The boundary conditions was assumed that the top and bottom wall of the air layer have a heating and cooling surface, respectively, and this calculation model have a solid body with a cooling temperature of $20^{\circ}C$. As the results of simulations, the magnitudes of the velocity vectors and isotherms are increased proportionally to the tilt angles. As the tilt angle is increased, the mean Nusselt numbers are increased and the maximum value of the mean Nusselt number was appeared at tilt angle $\theta=75^{\circ}$.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.429-436
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• 1995

This paper describes a methodology for determination of representative CANDU feeder geometry and the pressure drops between inlet/outlet header and fuel channel in the primary loop. A code, MEDOC, was developed based on this methodology and helps perform a calculation of equivalent feeder geometry for a selected channel group on the basis of feeder geometry data (fluid volume, mass flow rate, loss factor) and given property data pressure, quality, density) at inlet/outlet header. The equivalent feeder geometry calculated based on this methodology will be useful fur the transient thermohydraulic analysis of the primary heat transport system for the CANDU heavy water-cooled pressure tube reactor.

• The Korean Journal of Ceramics
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• 제4권2호
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• pp.136-140
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• 1998

This work demonstrates a method for modeling of electrical conductivity in high-temperature proton-conducting oxides. Total conductivity was calculated assuming that it comprises partial conductivities contributed by protons, oxygen ions and electron holes. From the polt $\sigma_{tot}$ vs. $po_2\;{1/4}$ in wet atmosphere, thermodynamic and kinetic parameters were obtained representing transport properties such as concentration and mobility of the charge-carrying defects. The formulas for the calculation of partial conduction were derived based on the defect structure of HTPCs. Illustrative calculation were made for $SrCe_{0.95}Yb_{0.05}O_{2.975}$ system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제18회 학술발표대회 논문초록집
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• pp.65-69
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• 2002

Unsteady vaporization of a droplet quiescent in a high pressure environment are studied with emphasis placed oil the modeling of equilibrium at vapor-liquid interface. Complete set of conservation equations for liquid and gas phases is numerically time integrated. Vapor-liquid interfacial thermodynamics are solved by f]ash equilibrium calculation method. The model was proper]y validated with experiment and the improvement in the solution accuracy was made. Vaporization of n-pentane fuel droplet in nitrogen background gas is examined. Effects of ambient gas solubility, property variation, transient diffusion, and multicomponent transport on the droplet vaporization are investigated systematically. High-pressure effects on the droplet vaporization is examined and discussed.

• 대한기계학회논문집
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• 제10권1호
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• pp.50-55
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• 1986

본 연구에서는 경계면에 맞춘 좌표계를 이용한 mapping을 통하여 37개봉으로 구성된 유로에서의 전달현상을 분석하였다.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.2087-2098
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• 2003

The development of numerical mathematical model to calculate both the static and dynamic characteristics of a multi-shaft gas turbine consisting of a single combustion chamber, including advanced cycle components such as intercooler and regenerator is presented in this paper. The numerical mathematical model is based on the simplified assumptions that quasi-static characteristic of turbo-machine and injector is used, total pressure loss and heat transfer relation for static calculation neglecting fuel transport time delay can be employed. The supercharger power has a cubical relation to its rotating velocity. The accuracy of each calculation is confirmed by monitoring mass and energy balances with comparative calculations for different time steps of integration. The features of the studied gas turbine scheme are the starting device with compressed air volumes and injector's supercharging the air directly ahead of the combustion chamber.

• Nuclear Engineering and Technology
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• 제44권2호
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• pp.177-198
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• 2012

This paper reviews the fast reactor physics and computational methods. The basic reactor physics specific to fast spectrum reactors are briefly reviewed, focused on fissile material breeding and actinide burning. Design implications and reactivity feedback characteristics are compared between breeder and burner reactors. Some discussions are given to the distinct nuclear characteristics of fast reactors that make the assumptions employed in traditional LWR analysis methods not applicable. Reactor physics analysis codes used for the modeling of fast reactor designs in the U.S. are reviewed. This review covers cross-section generation capabilities, whole-core deterministic (diffusion and transport) and Monte Carlo calculation tools, depletion and fuel cycle analysis codes, perturbation theory codes for reactivity coefficient calculation and cross section sensitivity analysis, and uncertainty analysis codes.

• 한국안전학회지
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• 제9권2호
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• pp.3-11
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• 1994

This study discribes result of comparision of two other numerical method, method of characteristics (MOC) and Lax-Wendroff method(LWM) applied at wave action analysis of Intake and exhaust pipe. Partiality FCT(Flux Correct Transport) scheme is appeneded to LWM to protest unacceptable overshoots, occuring near discontinuity. The final conclusion of this study is that MOC should be replaced by a second order finite difference approach(such as the LW method). Clear benefits we can get by change are faster calculation, higher accuracy, conservation of mass and consistent calculation method.

• 한국농공학회논문집
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• 제48권5호
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• pp.83-93
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• 2006

In unsaturated porous media, the air-water interface (AWI) plays an important role in removing of biocolloids such as bacteria, viruses, and protozoan (oo)cysts. In this study, four models related to calculation of specific AWI area are analyzed to determine the appropriate model, and the selected models are verified using the previously reported experimental data. The results indicate that the modified model from Niemet et al. (2002) is the most appropriate tool for calculating the specific AWI area using the van Genuchten (1980) parameters obtained from the water retention curve. Hence, it is expected that this model could be used to quantitatively determine the attachment of biocolloids to AWI in the transport modeling of biocolloids in unsaturated porous media.