scholarly journals Numerical Simulation to Determine the Effect of Topological Entropy on the Effective Transport Coefficient of Unidirectional Composites

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 423
Author(s):  
Carlos Pacheco ◽  
Romeli Barbosa ◽  
Abimael Rodriguez ◽  
Gerko Oskam ◽  
Miguel Ruiz-Gómez ◽  
...  
Keyword(s):  
Topological Entropy ◽  
Transport Coefficient ◽  
Design Tool ◽  
Two Phase ◽  
Transport Efficiency ◽  
Sem Image ◽  
Statistical Reconstruction ◽  
Surface Fraction ◽  
Effective Transport ◽  
Volume Method

The influence of topological entropy (TS) on the effective transport coefficient (ETC) of a two-phase material is analyzed. The proposed methodology studies a system of aligned bars that evolves into a stochastic heterogeneous system. This proposal uses synthetic images generated by computational algorithms and experimental images from the scanning electron microscope (SEM). Microstructural variation is imposed for statistical reconstruction moments by simulated annealing (SA) and it is characterized through TS applied in Voronoi diagrams of the studied systems. On the other hand, ETC is determined numerically by the Finite Volume Method (FVM) and generalized by a transport efficiency of charge (ek). The results suggest that our approach can work as a design tool to improve the ETC in stochastic heterogeneous materials. The case studies show that ek decreases when TS increases to the point of stability of both variables. For example, for the 80% surface fraction, in the particulate system of diameter D = 1, ek = 50.81 ± 0.26% @ TS = 0.27 ± 0.002; when the system has an agglomerate distribution similar to a SEM image, ek = 45.69 ± 0.60% @ TS = 0.32 ± 0.002.

scholarly journals Effect of An Image Resolution Change on the Effective Transport Coefficient of Heterogeneous Materials

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3757 ◽  
Author(s):  
Abimael Rodriguez ◽  
Romeli Barbosa ◽  
Abraham Rios ◽  
Jaime Ortegon ◽  
Beatriz Escobar ◽  
...  
Keyword(s):  
Transport Coefficient ◽  
Statistical Study ◽  
Image Resolution ◽  
Minimum Size ◽  
Image Size ◽  
Statistical Behavior ◽  
Effective Transport ◽  
Electrochemical Electrodes ◽  
Volume Method ◽  
Annealing Method

Electrochemical electrodes comprise multiple phenomena at different scales. Several works have tried to model such phenomena using statistical techniques. This paper proposes a novel process to work with reduced size images to reconstruct microstructures with the Simulated Annealing method. Later, using the Finite Volume Method, it is verified the effect of the image resolution on the effective transport coefficient (ETC). The method can be applied to synthetic images or images from the Scanning Electron Microscope. The first stage consists of obtaining the image of minimum size, which contains at least 98% of the statistical information of the original image, allowing an equivalent statistical study. The image size reduction was made by applying an iterative decimation over the image using the normalized coarseness to compare the amount of information contained at each step. Representative improvements, especially in processing time, are achieved by reducing the size of the reconstructed microstructures without affecting their statistical behavior. The process ends computing the conduction efficiency from the microstructures. The simulation results, obtained from two kinds of images from different materials, demonstrate the effectivity of the proposed approach. It is important to remark that the controlled decimation allows a reduction of the processor and memory use during the reconstruction and ETC computation of electrodes.

Particle Transport Coefficient (PTC) and Phase-Efficiency Diagram: A New Perspective to Evaluate Three-Phase Particle-Laden Flow

2020 ◽  
Author(s):  
Zhifeng Zhang ◽  
Antoine Jean-Claude Jacques Pruvot ◽  
Pablo Cisternas ◽  
James McAndrew
Keyword(s):  
Particle Transport ◽  
Transport Coefficient ◽  
Vertical Direction ◽  
Environmental Cost ◽  
Mathematical Form ◽  
Horizontal Pipe ◽  
Carrier Fluid ◽  
Transport Efficiency ◽  
Three Phase ◽  
New Perspective

Abstract Many technologies have been developed to improve the ability of fluids to transport particles. However, the evaluation of particle transport efficiency remains challenging, especially in complex flow such as three-phase flow. In the present research, theoretical and experimental work is conducted to develop a new perspective of evaluating particle transport technologies, particle transport coefficient (PTC) as the particle transport distance per unit volume of water consumption considering the transport efficiency and environmental cost. The mathematical form of the PTC for the steady-state transport case is derived, followed by three special transport cases: (a) PTC = 0 when particle settled or stuck, (b) PTC = infinity in the vertical direction, considering gravity or buoyant with carrier fluid stationary, while PTC = 0 in a horizontal pipe due to particle settlement; and (c) PTC = 2 for an infinitely small particle at the center of a fully-developed laminar flow in a pipe. Furthermore, the fluid property and surface property influence on PTC are experimentally demonstrated. We believe the proposed approach can promote the development of particle transport technologies.

scholarly journals The Influence of Combined Turbulators on the Hydraulic-Thermal Performance and Exergy Efficiency of MWCNT-Cu/Water Nanofluid in a Parabolic Solar Collector: A Numerical Approach

2021 ◽  
Vol 9 ◽  
Author(s):  
Yacine Khetib ◽  
Ammar Melaibari ◽  
Radi Alsulami
Keyword(s):  
Solar Collector ◽  
Volume Fraction ◽  
Numerical Approach ◽  
Exergy Efficiency ◽  
Multiphase Model ◽  
Two Phase ◽  
Simpler Algorithm ◽  
Fluent Software ◽  
Parabolic Geometries ◽  
Volume Method

The present research benefits from the finite volume method in investigating the influence of combined turbulators on the thermal and hydraulic exergy of a parabolic solar collector with two-phase hybrid MWCNT-Cu/water nanofluid. All parabolic geometries are produced using DesignModeler software. Furthermore, FLUENT software, equipped with a SIMPLER algorithm, is applied for analyzing the performance of thermal and hydraulic, and exergy efficiency. The Eulerian–Eulerian multiphase model and k-ε were opted for simulating the two-phase hybrid MWCNT-Cu/water nanofluid and turbulence model in the collector. The research was analyzed in torsion ratios from 1 to 4, Re numbers from 6,000 to 18,000 (turbulent flow), and the nanofluid volume fraction of 3%. The numerical outcomes confirm that the heat transfer and lowest pressure drop are relevant to the Re number of 18,000, nanofluid volume fraction of 3%, and torsion ratio of 4. Furthermore, in all torsion ratios, rising Re numbers and volume fraction lead to more exergy efficiency. The maximum value of 26.32% in the exergy efficiency was obtained at a volume fraction of 3% and a torsion ratio of 3, as the Re number goes from 60,000 to 18,000.

scholarly journals An adaptive finite-volume method for a model of two-phase pedestrian flow

2011 ◽  
Vol 6 (3) ◽  
pp. 401-423 ◽  
Author(s):  
Stefan Berres ◽  
◽  
Ricardo Ruiz-Baier ◽  
Hartmut Schwandt ◽  
Elmer M. Tory ◽  
...  
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Pedestrian Flow ◽  
Two Phase ◽  
Volume Method

A HLLC-type finite volume method for incompressible two-phase flows

2020 ◽  
Vol 213 ◽  
pp. 104715
Author(s):  
Rihua Yang ◽  
Heng Li ◽  
Aiming Yang
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Two Phase Flows ◽  
Two Phase ◽  
Volume Method
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