• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.362-364
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• 2001

Every engineering discipline has, in recent year, felt the impact of computer-aided analysis and design Normally the studies of power system analysis by computer are load flow, short circuit and harmonic calculation, the amount the voltage deviates from motor starting, reliability and system stability. These studies are very important from the operating and planning points of power system. This paper presents analysis of load flow, short circuit current calculation, the effect for voltage deviation of induction motor starting and harmonic distortion in power system of continuous casting(C. C) plant. The resulting of analysis is applied the configuration and design engineering of power system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.252-256
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• 1999

In this research, the performance predictions of the submersible mixer were investigated. The variation of the performance characteristics by changing the impeller design parameters were discussed through the flow calculation results by using a commercial program, FLUENT. The performance of the submersible mixers is related to the velocity diffusion profiles downstream of the impeller and also the required input motor power to mix the fluid. In this study, the various design parameters such as the number of blade, the hub and tip diameters, the impeller blade profiles and revolution speed of the blades were taken for the fixed values. The blade sweep direction, the chord length distribution along with the radius of the blade and the inlet blade angle were changed to make different testing models. The flow calculation results show the effect of the changed design parameters on the performance of the submersible mixers and also give some helpful information for designing more efficient submersible mixers.

• International Journal of Fluid Machinery and Systems
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• 제9권1호
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• pp.95-106
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• 2016

A method of optimization design for the blade profile of a centrifugal impeller by controlling velocity distribution is presented, and a plenum fan is successfully designed. This method is based on the inner flow calculation inside the centrifugal impeller, and is related to the distribution of relative velocity. The results show that after optimization, the boundary layer separation on the suction surface has been inhibited and the stability of plenum fan is improved. The flow at the impeller outlet is also studied, and the jet-wake pattern at the impeller outlet is improved obviously by optimization. The calculation result shows that the static pressure and static pressure efficiency can be increased by 15.4% and 21.4% respectively.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.251-253
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• 2003

This paper discusses some practical problems of the determination of ship wave resistance from flow calculation and the model test. there are so many kind of CFD program as FLUENT, WAVIS, SHIPFLOW, COMET etc. for finding optimized hull. we should know how much percent we trust the program. so if we gather computed values of the wave resistance we'll able to get more accurated values of presumptive.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.50-53
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• 2003

This Paper proposes the new method of Nodal Price calculation on nonoptimal condition of power system. It uses Power Flow instead of Optimal Power Flow. We propose a idea of imaginary constraints at the first. And the proposed method is applied to IEEE-30 and results show the effectiveness of the method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.743-745
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• 1996

This paper presents an approach for the analysis of static voltage stability in power system. The proposed approach is based on multiple load flow calculation method using the redistribution algorithm of transmission loss, with which more realistic load flow solution can be obtained in the near of voltage collapse point. Some simulation results of the proposed approach show that the accuracy of static voltage stability analysis can be increased.

• 한국수소및신에너지학회논문집
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• 제30권5호
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• pp.385-394
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• 2019

The analysis of temperature behavior of a hydrogen tank during refueling is of significance to clarify the safety of the compressed hydrogen storage in vehicles since the temperature at a tank rises with inflow of hydrogen. A mass balance and an energy balance were combined to obtain analytical model for temperature change during the hydrogen refueling. The equation was coupled to Peng-Robinson-Gasem (PRG) equation of state (EOS) for hydrogen. The PRG EOS was adopted after comparison with other four different cubic EOSs. A parameter of the model was determined to fit data from experiments of various inlet flow rates and temperatures. The temperature and pressure change with refueling time were obtained by the developed model. The calculation results revealed that the extent of precooling was more effective than the flow rate control.

• 한국안전학회지
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• 제14권4호
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• pp.60-70
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• 1999

In this study, the computer code for the optimal design of road tunnel ventilation system based on one-dimensional analysis of the air flow was developed. The control volume method was used to calculate the air velocities and the concentration distribution of pollutants(CO, NOx, Particulate) for various tunnel ventilation system. This code was validated by comparing the calculation results to the practical design data for the road tunnel ventilation system. The calculation results were in accord with the practical design data.

• 환경위생공학
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• 제13권3호
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• pp.43-51
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• 1998

This study presents a numerical method for calculating gas flow around a sanitary landfill gas vent, when gas flows by pressure. The method described is a three-dimensional compartmental model and includes methods to determine the dimensions for the model. Using the numerical method, controll of press and gases flowing out to the air through final cover soil, and degine of sanitary landfill gas vents.

• Journal of Mechanical Science and Technology
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• 제16권3호
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• pp.386-394
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• 2002

The present work is aimed at investigating an unusual variation in flow and performance characteristics of a small propeller fan at low flow rates. A performance test of the fan showed dual performance characteristics, i.e., radial type characteristics at low flow rates and axial type at high flow rates. Dual performance characteristics of the fan are numerically investigated using viscous flow calculations. The Finite Volume Method is used to solve the continuity and Navier-Stokes equations in the flow domain around a fan. The performance parameters and the circumferentially averaged velocity components obtained from the calculations are compared with the experimental results. Numerical values of the performance parameters show good agreement with the measured values. The calculation simulates the steep variations of performance parameters at low flow rates and shows the difference in the flow structure between high and low flow rates. At a low flow coefficient of $\Phi$=0.2, the flow enters the fan in an axial direction and is discharged radially outward at its tip, which is much like the flow characteristics of a centrifugal fan. The centrifugal effect at low flow rates makes a significant difference in performance characteristics of the fan. As the inlet flow rate increases, flow around the fan changes into the mixed type at $\Phi$=0.24 and the axial discharge at $\Phi$=0.4.