• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.11
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• pp.1417-1427
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• 2000

A flow stabilizer, which is made of a honeycomb and three different mesh screens, is located downstream of a butterfly-type valve, for the reduction of flow disturbances behind the valve. Mean flow and turbulence measurements as well as flow visualizations are conducted in the downstream region of the deepens the non-uniformity of the streamwise velocity component and turbulence. The mesh screens considerably reduce the turbulence and enhance the uniformity of mean velocities. The combination of the honeycomb and the three mesh screens results in an efficient reduction in the flow disturbances. In addition, the flow stabilizer proves to have a good performance in the suppression of turbulence at a short distance.

• Journal of computational fluids engineering
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• v.9 no.4
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• pp.13-19
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• 2004

Flow distribution of a mid-size vehicle in engine room was investigated numerically to analyze the flow performance of given design cases in a front body of the mid-size vehicle. The data analyzed are the mass flow rate at the upper and lower openings, in the radiator, and the degree of non-uniformity of the velocity field at the inlet of the radiator. It is presented that the shape of the front end and the presence of the undercover greatly affect the flow fields, therefore, the flow performance.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.359-364
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• 2000

The fluid flow, heat transfer and the local mass fi-action of chemical species in the chemical vapor deposition(CVD) manufacturing process are numerically studied. The deposition of silicon from dilute silane is hydrogen carrier gas in a horizontal CVD reactor is investigated. The effect of inlet carrier gas velocity, mass fraction of silane, susceptor angle on the deposition thickness and uniformity was represented.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.796-802
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• 2005

Numerical analysis has been conducted for improving air flow characteristics in the exhaust aftertreatment system of diesel-fueled passenger cars by changing axial length and cone shape of a DPF diffuser. The results of air velocity and static pressure distributions along with air flow uniformity results suggest that a diffuser shape with 2D or 3D function type is better for air flow patterns in front of a DPF.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.85-93
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• 2001

Minimized canister flow restriction and maximized flow uniformity are desired to maximize a purge capability. With the impending ORVR(On Board Refueling Vapor Recovery) systems, the reduction of restriction and increase of flow uniformity in a carbon canister becomes even more critical to meet the stringent regulation. In this study, three-dimensional numerical simulations have been performed to investigate the three-dimensional internal flow patterns in a carbon canister during purge. The effects of the declined angle of the purge pipe and the number of partitions on the pressure drop and purge efficiency in a carbon packed bed are examined. Results show that the purge efficiency and space velocity distribution are affected in the upstream region of 40% of total canister bed by porosity of carbon granule and angle of purge pipe. It is also found that the purge efficiency decreases with increasing the number of partitions.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.72-79
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• 1996

The recent trend of higher output engines with more auxiliary parts is resulting in greater heat generation in the engine compartment. In order to maximize the heat dissipation and eliminate the inefficient flow in the engine compartment, it is necessary to understand the flow field under the hood. In this respect, experimental study as well as numerical analysis should be conducted. The automated measuring system was constructed to obtain three dimensional mean flow data with high accuracy. The measurements have been made on a vehicle with a steady incoming air flow. The result shows that there exists a high degree of non-uniformity in the mean flow velocity at the front of radiator.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.4
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• pp.303-315
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• 1990

Uniformity of velocity is quite important design points of a vertical laminar flow type clean room. In the present paper, flows in a room with a bottom pannel are numerically simulated by using a low-Reynolds number $k-{\epsilon}$ model, and a new flow model of the pannel are suggested. Resistance coefficient of the pannel and size of the exhaust channel show considerable effects on flow pattern and uniformity of flow on the bottom. Reflection coefficient also has important roles. A possibility to obtain the uniform and unidirectional flow is tested by adjusting the distribution of resistance coefficient of the pannel. Such a numerical simulation of the flow will be a good method to get optimun design parameters.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.61-63
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• 2015

In the low pressure selective catalytic reduction (LP SCR) system, the uniformity of both ammonia concentration and exhaust gas flow at the SCR catalyst layer are important design factor for the efficient SCR-deNOx performance. According to the shape of the guide vane and static mixer, numerical simulations were conducted to analyze flow patterns and finally to find out the appropriate alternative for uniform flow at the front of catalyst in the real scale LP SCR reactor. The variations of gas velocity and ammonia concentration were quantitatively evaluated. Based on the present results, the shape was devised to satisfy the design criteria.

• Applied Science and Convergence Technology
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• v.26 no.6
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• pp.189-194
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• 2017

Effects of gas injection scheme and rf driving current configuration in a dual turn inductively coupled plasma (ICP) system were analyzed by 3D numerical simulation using CFD-ACE+. Injected gases from a tunable gas nozzle system (TGN) having 12 horizontal and 12 vertical nozzles showed different paths to the pumping surface. The maximum velocity from the nozzle reached Mach 2.2 with 2.2 Pa of Ar. More than half of the injected gases from the right side of the TGN were found to go to the pump without touching the wafer surface by massless particle tracing method. Gases from the vertical nozzle with 45 degree slanted angle soared up to the hottest region beneath the ceramic lid between the inner and the outer rf turn of the antenna. Under reversed driving current configuration, the highest rf power absorption region were separated into the two inner islands and the four peaked donut region.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.4
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• pp.328-334
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• 2006

Industrial electrostatic precipitators require a highly uniform velocity distribution in the collecting chamber. Increasing divergence angle of a diffuser makes a non-uniformity flow distribution characteristics on the diffuser exit. This paper provides CFD results of optimum positions and opening rates of perforated plates which were installed in the electrostatic precipitator. The considered divergence angels were 60 degree and 90 degree. In 90 degree diffuser, a blanking method was used.