Numerical Analysis of a Compressor Type of Dehumidifier: (I) Fluid Flow

A three-dimensional simulation of a compressor dehumidifier was conducted by applying a porous model for condenser and evaporator, and a moving reference frame for the fan. A physical model was simulated for the unit cell of the actual shape of a fin-tube, and the parameters of viscous resistance and initial resistance were obtained. With these values, the porous model showed close agreement with the physical model within a reasonable computation time. A uniform flow across the evaporator and the condenser is desirable for high performance of the dehumidifier. Surface averaged velocity, standard deviation of velocity, and uniformity were chosen as indicators of the design object. A case study showed that two factors, (i) reducing the space between the evaporator and the condenser and (ii) introducing a cover to reduce the by-passing air flow, have the strongest influence on the air distribution in this dehumidifier.

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Physical model features and validation status of three-dimensional simulation model for BWR in-vessel core degradation

Annals of Nuclear Energy ◽

10.1016/j.anucene.2017.03.021 ◽

2017 ◽

Vol 105 ◽

pp. 168-183 ◽

Cited By ~ 4

Author(s):

Tsuyoshi Okawa ◽

Shigeki Shiba ◽

Tetsuo Nakajima

Keyword(s):

Simulation Model ◽

Physical Model ◽

Three Dimensional ◽

Dimensional Simulation ◽

Model Features

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Effective Particle Size Representation for Erosion Wear in Centrifugal Pump Casings

Volume 1C, Symposia: Gas-Liquid Two-Phase Flows; Gas and Liquid-Solid Two-Phase Flows; Numerical Methods for Multiphase Flow; Turbulent Flows: Issues and Perspectives; Flow Applications in Aerospace; Fluid Power; Bio-Inspired Fluid Mechanics; Flow Manipulation and Active Control; Fundamental Issues and Perspectives in Fluid Mechanics; Transport Phenomena in Energy Conversion From Clean and Sustainable Resources; Transport Phenomena in Materials Processing and Manufacturing Processes ◽

10.1115/fedsm2017-69240 ◽

2017 ◽

Cited By ~ 2

Author(s):

Krishnan V. Pagalthivarthi ◽

John M. Furlan ◽

Robert J. Visintainer

Keyword(s):

Particle Size ◽

Fluid Dynamic ◽

Three Dimensional ◽

Computation Time ◽

Particle Simulation ◽

Computational Time ◽

Two Dimensional ◽

Wide Range ◽

Dimensional Simulation ◽

Three Dimensional Simulations

For the purpose of Computational Fluid Dynamic (CFD) simulations, the broad particle size distribution (PSD) encountered in industrial slurries is classified into a discrete number of size classes. Since mono-size simulations consume much less computational time, especially in 3D simulations, it would be advantageous to determine an equivalent single particle size representation which yields the same wear distribution predictions as the multi-size simulations. This work extends the previous two-dimensional study [1], which was for a specific PSD slurry flow through three selected pumps, to determine an effective equivalent mono-size representation. The current study covers two-dimensional simulations over a wide range of pumps of varying sizes (40 pumps), 2 inlet concentrations and 4 different particle size distributions. Comparison is made between the multi-size wear prediction and different possible representative mono-size particle wear predictions. In addition, a comparison of multi-size and different mono-size results using three dimensional simulations is also shown for a typical slurry pump as a sample case to highlight that the conclusions drawn for two dimensional simulation could hold good for three dimensional simulations as well. It is observed that by using a mono-size equivalent, the computation time is 20–25% of the computation time for multi-size (6-particle) simulation.

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Three-Dimensional Simulation of Water Management for High-Performance Proton Exchange Membrane Fuel Cell

SAE International Journal of Alternative Powertrains ◽

10.4271/2018-01-1309 ◽

2018 ◽

Vol 7 (3) ◽

pp. 233-247 ◽

Cited By ~ 7

Author(s):

Guobin Zhang ◽

Kui Jiao ◽

Renfang Wang

Keyword(s):

Water Management ◽

Fuel Cell ◽

High Performance ◽

Proton Exchange Membrane ◽

Three Dimensional ◽

Proton Exchange ◽

Dimensional Simulation ◽

Exchange Membrane

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On Contraction of Three-Dimensional Multiple Shear Mechanism Model for Evaluation of Large Scale Liquefaction Using High Performance Computing

Geosciences ◽

10.3390/geosciences9010038 ◽

2019 ◽

Vol 9 (1) ◽

pp. 38

Author(s):

Wataru Hotta ◽

Shunichi Suzuki ◽

Muneo Hori

Keyword(s):

High Performance ◽

Large Scale ◽

Three Dimensional ◽

Computation Time ◽

Parallel Computer ◽

Analysis Model ◽

Mechanism Model ◽

Shear Mechanism ◽

Material State ◽

Parallel Fem

For more reliable evaluation of liquefaction, an analysis model of higher fidelity should be used even though it requires more numerical computation. We developed a parallel finite element method (FEM), implemented with the non-linear multiple shear mechanism model. A bottleneck experienced when implementing the model is the use of vast amounts of CPU memory for material state parameters. We succeeded in drastically reducing the computation requirements of the model by suitably approximating the formulation of the model. An analysis model of high fidelity was constructed for a soil-structure system, and the model was analyzed by using the developed parallel FEM on a parallel computer. The amount of required CPU memory was reduced. The computation time was reduced as well, and the practical applicability of the developed parallel FEM is demonstrated.

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Reconstruction of Objects from their Projections Using Orthogonal Functions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071788 ◽

1973 ◽

Vol 31 ◽

pp. 268-269

Author(s):

Elrnar Zeitler

Keyword(s):

Unit Area ◽

Three Dimensional ◽

One Dimension ◽

Spatial Density ◽

Dimensional Representation ◽

Orthogonal Functions ◽

Object A ◽

Plane Normal ◽

Dimensional Object ◽

Spatial Density Distribution

Considering any finite three-dimensional object, a “projection” is here defined as a two-dimensional representation of the object's mass per unit area on a plane normal to a given projection axis, here taken as they-axis. Since the object can be seen as being built from parallel, thin slices, the relation between object structure and its projection can be reduced by one dimension. It is assumed that an electron microscope equipped with a tilting stage records the projectionWhere the object has a spatial density distribution p(r,ϕ) within a limiting radius taken to be unity, and the stage is tilted by an angle 9 with respect to the x-axis of the recording plane.

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Improved 3-D reconstruction using stereo computer graphics and multiple tilt EM images

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139524 ◽

1995 ◽

Vol 53 ◽

pp. 630-631

Author(s):

Lee D. Peachey ◽

Lou Fodor ◽

John C. Haselgrove ◽

Stanley M. Dunn ◽

Junqing Huang

Keyword(s):

Computer Graphics ◽

High Performance ◽

Transverse Section ◽

Three Dimensional ◽

Stereo Pair ◽

3D Reconstructions ◽

Video Cameras ◽

Biological Objects ◽

Microscope Images ◽

High Performance Computer

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.

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