• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.509-512
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• 2001

Recently, our country's piggery has been becoming large-sized and crowded gradually in scale. Thus, the environment in a piggery is getting worse, which leads to a drop in livestock's immunoactivity. Therefore, livestocks are exposured to many diseases(stress, hypertension, stomach ulcer etc.). In this paper, our intention is to design a low cost ozone-generating device with high capacity to maintain a reasonable ozone level, that is necessary for cleaning the environment in a piggery, but is not too high to cause any harmful influence to human beings and livestock. The results showed that the UV-lamp tube with baffle has an increase of 25% in ozone generation efficiency compared to without baffle and the short retention time of air or high inlet air rate shows high level of ozone.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.948-953
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• 1988

A technique applicated for physiologic correction of complex congenital cardiac disease suitable for Fontan procedure in which drainage of left superior vena cava and hepatocardiac vein to left atrium combined is described. We made one systemic venous baffle from left hepatocardiac vein to left superior vena cava and another systemic venous baffle from right inferior vena cava to the right superior vena cava with rigid prosthetic material[0.5mm thickness PTFE patch]. And then we anastomosed directly between the right sided atrial appendage and right pulmonary artery, and left-sided atrial wall beneath the appendage and left pulmonary artery. We believe that this procedure is superior to the method using intraatrial tube graft to divert the left hepatocardiac venous blood to right atrium, and applicable for physiologic correction of any complex congenital cardiac disease suitable for Fontan-type procedure in which anomalies of systemic venous drainage combined.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.201-207
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• 1998

A tube-type filter dam(or baffle with holes) for ferrous melt refining is applied to the tundish operation for molten steel having low carbon and ultra-low carbon. The changes in the total oxygen content insoluble aluminum content and the distribution of inclusion size in molten steel during tundish operation were in-vestigated at the pouring part strand and mold of tundish. Removal mechanism of inclusions is considered to be caused by buoyancy action of the filter dam better than filtration action and the size range of in-clusions filtrated by the filter dam was for 30-50$\mu\textrm{m}$. Decrease in deviation of inclusion content in molten steel was confirmed for appling the filter dam in comparison with using conventional dam and weir. Also the filter dam had the advantage of baffle with holes at lower part in the efficiency of inclusions removal.

• Journal of Power System Engineering
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• v.12 no.3
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• pp.32-37
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• 2008

The present work aims to determine the overall pressure losses in the shell from the point of entry of the fluid to the outlet point of fluid of shell and tube heat exchanger. The main contribution of the present work is concerned with calculating the pressure drop in the interior section and window section. Shell-side flow velocity distributions have been evaluated. We assume that the shell-side fluid is turbulent. The calculation procedure is based upon the Delaware method. Evaluation of pressure drop on the shell side will be helpful for a designer or manufacturer of a heat exchanger.

• 한국전산유체공학회:학술대회논문집
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• 1999.05a
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• pp.162-170
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• 1999

Numerical study has been peformed to develop a computer code for the design & optimal operating condition of SNCR(Selective Noncatalytic Reactor) for NOx reduction together with the analysis of the performance of vortex tube. Especially for the SNCR of the scale of industrial boiler, the required mixing and residence time of $NH_3$ solution was successfully tested numerically by the implementation of some baffle setups in a combustor. The introduction of interesting phenomena of vortex tube and similar system is made together with a theoretical hypothesis and simple cold flow simulation for the flow field analysis.

• Journal of computational fluids engineering
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• v.21 no.4
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• pp.28-32
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• 2016

In the previous study, it is proved by numerical simulation that the baffle shaped as the porous plate installed in the inlet chambers improves the redistribution of the flow injecting to the tube bundles. In the present study, numerical simulation has been performed to investigate the effects of the flow distributors on the thermal characteristics of the shell and tube heat exchangers. The flow fields have been analysed by the three-dimensional Navier-Stokes solvers including the thermal conditions on the shell sides. The numerical results showed that the presence of the baffles improves the redistribution of the heat transfer to the tube bundles though the overall performance drop slightly on the present flow conditions.

• Journal of Mechanical Science and Technology
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• v.17 no.5
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• pp.718-725
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• 2003

The present study addresses the distortion of the compression wave reflected from an open end of a shock tube. An experiment is carried out using the simple shock tube with an open end Computational work is also performed to represent the experimented flows. The second-order Total Variation Diminishing scheme is employed to numerically solve the unsteady, axisy-mmetric, inviscid, compressible governing equations. Both the experimented and predicted results are in good agreement. The generation and development mechanisms of the compression wave, which Is reflected from the open end of the shock tube, are obtained in detail from the present computations. The effect of size of the baffle plate at the open-end that causes the reflection of the incident expansion wave is found negligible. A good correlation is obtained for transition of the reflected compression wave to a shock wave inside the tube. The present data show that for a given wave length of the incident expansion wave the transition of the reflected compression wave to a shock wave can be predicted with good accuracy.

• Journal of Power System Engineering
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• v.16 no.4
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• pp.24-29
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• 2012

The numerical analysis by using CFX 11.0 commercial code was done for prediction of fluid flow and thermal field in the vertical heat exchanger. The present experimental studies were also conducted to investigate the effects of circulating solid particles on the fluid flow and temperatures in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which the solid particles of glasses (3 $mm{\Phi}$) were used in the fluidized bed with a smooth tube. The effect of circulation on the distance(L) of tube inlet and baffle plate was also examined. The present experimental and numerical results showed that the particles in the distance (Ds) of 15 mm showed a more efficient circulation without stacked the space and the LMTD(Log Mean Temperature Difference) in the fluidized bed type was much lower than that in the typical type shell and tube heat exchanger.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.150-154
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• 2012

A flow induced mechanical vibration and acoustic resonance should be considered at design stage because they are mainly occurred in the tube bank of boiler. Acoustic resonance is occurred when the vortex shedding frequency of tube bank coincides with the acoustic natural frequency of the cavity. Effective solution to avoid acoustic resonance is installing acoustic baffles in the tube banks parallelly inside of the flow cavity. Thus, location and number of acoustic baffles should be exactly calculated to eliminate the acoustic resonance. This paper presents case study of acoustic resonance due to inappropriate number and location of acoustic baffles. Measured frequency and mode in the study is verified by FEM acoustic modal analysis. The number and location of acoustic baffles to avoid acoustic resonance are calculated by using FEM acoustic modal analysis.

• Journal of ILASS-Korea
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• v.9 no.4
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• pp.24-30
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• 2004

Feedwater flowing tube side of number 5 high pressure feedwatrr heaters was heated by extracting steam from high pressure turbine and draining water from moisture separators and number 6 high pressure feedwater heaters and supplied into steam generators. Because the extracting steam from the high pressure turbine is two phase fluid of high temperature, high pressure, and high speed and flows to inverse direction after impinging to impingement baffle. the shell wall of the number 5 high pressure feedwater heater may be affected by flow accelerated corrosion. On May 14, 1999, Point Beach Nuclear Plant (PBNP) with operating at full power experienced a steam leak from rupture of shell side of number 4B feedwater heater. Also, d domestic nuclear power plant experienced a severe wall thinning of shell side of number 5A and 5B feedwater heaters. This paper describes the fluid mixing analysis study using PHOENICS code in order to get at the root of the shell wall thinning of the feedwater heaters. The sections included in the fluid mixing analysis model are around the number 5h feedwater heater shell including the extracting pipeline. To identify the relation between the local velocities and wall thinning. the local velocities according to the analysis results were compared with the distribution of the shell wall thickness by ultrasonic test.