• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1470-1476
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• 2002

The goal of this work is to design and build an implantable artificial lung that can be inserted as a whole into a large vein in the body with the least effect on cardiovascular hemodynamics. The experimental results demonstrate that the pressure drop is not entirely related to viscosity effects. The friction factor decreases with an increase in the number of tied-hollow fibers at a constant Reynolds number A uniform flow pattern without stagnation is observed at all numbers of tied hollow fibers tested. The tied hollow fiber module, built in this study with 3 cm of outer diameter of module. 380 m of outer diameter of tied hollow fiber, and 700 number of tied hollow fiber with length of 60 cm, which shows a pressure drop of 13-16 mmHg, satisfies the required pressure drop qualifying 15 mmHg as an intravascular artificial lung.

• 한국기계연구소 소보
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• s.17
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• pp.133-144
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• 1987

Since the towing tank was operated from early 1979, the test and analysis methods have been established and applied for the performance prediction of ships. Especially the analysis programs for the resistance test ('EHP') and self-propulsion test ('DHP') based on the 1978 ITTC performance prediction method was modified as a name of 'PPTT' in order to include the form factor calculation, two-dimensional analysis method, the prediction on multi-screw ship and the organization of data filing system. Recently the program 'PPTT' was improved to cover the procedure of data fairing, the analysis of propeller-open-water test results carried out at low and high Reynolds numbers, etc. This paper describes the newly improved analysis program 'PTI'.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2731-2736
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• 2007

In this paper, incompressible flow over a cylinder near a plane wall using the Immersed Boundary. Finite Difference Lattice Boltzmann Method (IB-FDLBM) is implemented. In this present method, FDLBM is mixed with IBM by using the equilibrium velocity. We introduce IBM so that we can easy to simulate bluff-bodies. With this numerical procedure, the flow past a circular cylinder near a wall is simulated. We calculated the flow patterns about various Reynolds numbers and gap ratios between a circular cylinder and plane wall. So these are enabled to observe for vortex shedding. The numerical results are found to be in good agreement with those of previous studies.

• Tribology and Lubricants
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• v.19 no.3
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• pp.139-145
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• 2003

In this paper, static characteristics of a cryogenic hydrostatic journal bearing which has 2-rows staggered recesses are numerically analyzed. The regime of operation of this bearing is fully turbulent with large fluid inertia effects. The turbulent lubrication equation is solved under the assumption that turbulence parameters are decided by the Reynolds numbers. Pressure drop caused by inertia effect at the recess edge is considered in this analysis. Also density and viscosity of working fluid are considered as function of only pressure. Numerical results for a cryogenic Hydrostatic journal bearing show pressure distribution, load capacity, flow rate, and recess pressure. The effects of turbulent flow, pressure drop and variable liquid properties are discussed.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.117-123
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• 2004

The burning characteristics of interacting coal particles in a convective flow are numerically investigated at various Reynolds numbers. The transient combustion of 2-dimensionally arranged particles, both the fixed particle distances of 5 radii to 20 radii horizontally and 3 radii to 24 radii vertically, is studied. The results obtained from the present numerical analysis reveal that the transient flame configuration and retardation of particle temperature augmentation with the horizontal or vertical particle spacing substantially influence devolatilization process and carbon conversion ratio of interacting particles. Volatile release and carbon conversion ratio of the second particle with decreasing horizontal and vertical particle spacing decrease gradually, whereas those of the first particle with decreasing vertical particle spacing increases due to flow acceleration. When the vertical particle spacing is smaller than $6R_{o}$, volatile release and carbon conversion ratio of the second particle decrease greatly due to reduction of flame penetration depth.

• Journal of Power System Engineering
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• v.13 no.2
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• pp.36-41
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• 2009

An experimental investigation was conducted to examine the fluid flow resistance in the rectangular channel with two inclined wire screen baffles. Two different types of wire screens; dutch weave and plain weave, were used as baffle devices in this experiment. Three kinds of baffles with different mesh specifications were made up of dutch type and four different kinds of baffles were made up of plain weave type. The stainless steel wire screen baffles were mounted on the bottom wall with varied angle inclination. Reynolds numbers were varied from 23,000 to 57,000. Results show that the mesh number of baffles plays an important role on friction factor behaviour. It is found that the baffle with the most number of meshes (type SA) has the highest fluid flow resistance.

• Journal of computational fluids engineering
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• v.12 no.1
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• pp.35-42
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• 2007

This paper describes a recent development on the divergence free basis function based on a hermite stream function and verifies its validity by comparing results with those from a modified residual method known as one of stabilized finite element methods. It can be shown that a proper choice of degrees of freedom at a node with a proper arrangement of the hermite interpolation functions can yield solenoidal or divergent free interpolation functions for the velocities. The well-known cavity problem has been chosen for validity of the present algorithm. The comparisons from numerical results between the present and the modified residual showed the present method yields better results in both the velocity and the pressure within modest Reynolds numbers(Re = 1,000).

• Journal of computational fluids engineering
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• v.4 no.1
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• pp.27-33
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• 1999

Spiral tube heat exchangers can find numerous applications in many engineering fields. Flow in spiral tubes is interest to engineers due to occurrence of secondary flow which enhances the cross-sectional mixing and the heat transfer rate. In the present study, an incompressible viscous 3-D flow in spiral tubes with rectangular cross-section of various torsion rate and Reynolds number is studied by using a finite volume method. It is shown that the axial velocity profile is affected by the secondary flow motion. Because there is some difference from correlation proposed by Hur et al., a lot of analysis and arrangement of experimental results are needed. This study showed the results of variation of hydrodynamic entry length for torsion and Re numbers.

• KSBB Journal
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• v.16 no.3
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• pp.241-245
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• 2001

Mass transfer rates have been measured for the extraction of enzyme from aqueous solution into a reverse-micelle phase at $25^{\circ}C$. The 420 mL vessel was carefully designed to maintain a planar interface between the aqueous and solvent phases, so allowing precise measurement of interfacial area, has been investigated. Sodium di-2-ethylhexyl sulfosuccinate(AOT) was the surfactant used. Factors varied included: agitator speed, pH, ionic strength and surfactant concentration. Samples were taken from the solvent phase at 15min intervals, and the amount of enzyme extracted was measured by UV absorption at 280 nm. The observed Sherwood numbers for the aqueous phase $Sh_1$were correlated interms of the aqueous phase Reynolds number $Re_1$, and modified Schmidt number $Sc_1$. $Sh_1=0.664Re_1^{0.5}Sc_1^{0.33}$

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.3
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• pp.637-643
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• 2001

Two-phase flow in a combustion chamber is experimentally analyzed according to the five different conditions in the Reynolds numbers of $1.02{\times}10^4$. As the height difference between the primary and secondary jets increases, the secondary has a little less effect on the primary one in the case on the same height difference, the primary jet is affects as the velocity of th secondary on increase. The primary-jet flow field cause the particle concentration since is controlled by the velocity of secondary jet, the height difference, and the angle of primary jet in the test section.