• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1880-1884
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• 2004

To analyze the fluid flow and thermal characteristics in a nanoscale system, the planar Poiseuille flow of a Lennar-Jones liquid through parallel plates formed by fixed atoms is studied using nonequilibrium molecular dynamics simulations. The role of important simulation parameters such as the channel width, the magnitude of external field, the temperatures of the top and bottom plates, and the interaction potential parameter between fluid and wall atoms, which affect flow patterns and heat transfer rate inside the channel, are investigated. Under the various simulation conditions, interesting phenomena deviated from the continuum predictions have found.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.196-208
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• 2017

This study presents an experimental work in a petrochemical company for scanning a buried pipeline using $Tc^{99m}$ radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, $Tc^{99m}$ radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.2
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• pp.71-77
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• 2000

A multi-region model for solute transport through saturated soils has been developed to describe preferential flow. The model consists of numerous discrete pore groups, which are characterized by a discrete dispersion coefficient, flow velocity, and porosity . The hydraulic properties for each pore group are derived from a soil's hydraluic conductivity and soil water characteristic functions . Flow in pore group is described by the classical advection-disersion equation (ADE). An implict finite difference scheme was applied to the governing equation that results in a block-tridiagonal system of equations that is very efficient and allows the soil to be divided into any number of pore groups. The numerical technique is derived from methods used to solve coupled equations in fluid dynamics problems and can also be applied to the transport of interacting solutes. The results of the model are compared to the experimental data from published papers. This paper contributes on the characteristics of the method when applied to the parallel porosity model to describe preferential flow of solutes in soil.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.473-488
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• 1988

This paper is concerned with the prediction of two dimensional turbulent flows in the parallel plate with the repeated cylindrical blockages. The purpose of this paper is to find the effect of the eccentricity and the pitch of the repeated cylindrical blockages on the flow field, heat transfer coefficients and friction factors. A special technique is developed for the solution of the fully developed turbulent recirculating flow, in which the flow field varies periodically. A non-othogonal coordinate transformation is employed to solve the momentum and the energy equations. The results show that the pitch ratio or the eccentricity of the repeated blockages become smaller, or the Reynolds number of the flow larger, friction factors and heat transfer coefficients increase.

• Journal of applied mathematics & informatics
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• v.41 no.2
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• pp.401-411
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• 2023

The effects of longitudinal velocity dusty fluid flow in a weak magnetic field are investigated in this paper. An external uniform magnetic field parallel to the flow of dusty fluid influences the flow of dusty fluid. Besides that, the problem under investigation is completely defined in terms of identifying parameters such as longitudinal velocity (u), Hartmann number (M), dust particle interactions β, stock resistance γ, Reynolds number (Re) and magnetic Reynolds number (Rm). While using suitable transformations of resemblance, The governing partial differential equations are transformed into a system of ordinary differential equations. The Hankel Transformation is used to solve these equations numerically. The effects of representing parameters on the fluid phase and particle phase velocity flow are investigated in this analysis. The magnitude of the fluid particle is reduced significantly. The result indicates the magnitude of the particle reduced significantly. Although some of our numerical solutions agree with some of the available results in the literature review, other results differs because of the effect of the introduced magnetic field.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.103-109
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• 2024

A nonlinear numerical analysis of orientation and velocity fields of the full Ericksen-Leslie theory for a nematic liquid crystal under shear flow is given. We obtained for the first time the three-dimensional orientation and two component velocity profiles evolutions for both in- and out-of-shear plane orientation anchorings. Complex evolution routes to steady state were found even for shear aligning nematic. As the Ericksen number increases monotonic evolution of velocity and orientation shifts towards multi-region nucleating director rotation growth with complex secondary flow generations. We found that contrary to the in-shear-plane anchorings like homeotropic or parallel anchorings, binormal anchoring gives rise to substantial non-planar three-dimensional orientation with nonzero secondary flow.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.175-191
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• 2002

The equations of a polar fluid of hydromagnetic fluctuating through a porous medium axe cast into matrix form using the state space and Laplace transform techniques the resulting formulation is applied to a variety of problems. The solution to a problem of an electrically conducting polar fluid in the presence of a transverse magnetic field and to a problem for the flow between two parallel fixed plates is obtained. The inversion of the Laplace transforms is carried out using a numerical approach. Numerical results for the velocity, angular velocity distribution and the induced magnetic field are given and illustrated graphically for each problems.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.7.1-7.1
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• 2005

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.136-145
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• 1993

This paper considers a reliability problem as a special type of flow problem and presents an algorithm to evaluate the exact 2-terminal reliability of networks by using a backtracking technique. It employs a polygon-to-chain reduction in addition to series and parallel reduction techniques to reduce execution time. In comparisons, it presents a much better performance than other algorithms known to us. We also propose a methodology to apply the algorithm for approximation of the system reliability.

• Journal of Biomedical Engineering Research
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• v.7 no.1
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• pp.75-79
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• 1986

In this paper, a multigate pulsed doppler system with parallel signal processing which enables the transcutaneous assesment of the blood-flow velocities of five adjacent sample volumes is developed. The outputs of the system are audio signals, velocity curves and velocity profiles of 5 adjacent sample volumes. We have applied to the major superficial arteries and obtained the detailed information about the time dependent blood-flow behavior.