Distribution characteristics of exhaust gases and soot particles in a wall-flow ceramics filter

Wu, Guojiang; Кузнецов, А. В.; Jasper, Warren J.

doi:10.1016/j.jaerosci.2011.04.003

Cited by 34 publications

(14 citation statements)

References 29 publications

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“…Further, it is very important to explain how nanofluid flow is possible in a porous medium. It has been shown by Wu et al (2010Wu et al ( , 2011 that the porous matrix works as a filter for nanoparticles. This demonstrates that we are simulating here a real physics problem of natural convection in a square porous cavity filled with a nanofluid using the mathematical nanofluid model proposed by Buongiorno (2006) as in many papers pioneered by Nield and Kuznetsov (2009a, b, 2010 and Kuznetsov and Nield (2010a, b, c, d, 2011a, b, c, 2013.…”

Section: Basic Equationsmentioning

confidence: 99%

Natural Convection in a Square Porous Cavity with Sinusoidal Temperature Distributions on Both Side Walls Filled with a Nanofluid: Buongiorno’s Mathematical Model

2014

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Natural convection in a two-dimensional, square porous cavity filled with a nanofluid and with sinusoidal temperature distributions on both side walls and adiabatic conditions on the upper and lower walls is numerically investigated. The flow is assumed to be slow so that advective and Forchheimer quadratic terms are ignored in the momentum equation. The applied sinusoidal temperature is symmetric with respect to the midplane of the enclosure. Numerical calculations are produced for Rayleigh numbers in the range of 10-10 4 in comparison with other authors. The present models, in the form of an in-house computational fluid dynamics code, have been validated successfully against the reported results from the open literature. It is found that the results are in very good agreement. Results are presented in the form of streamlines, isotherm contours, and distributions of the average Nusselt number.

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Section: Basic Equationsmentioning

confidence: 99%

Natural Convection in a Square Porous Cavity with Sinusoidal Temperature Distributions on Both Side Walls Filled with a Nanofluid: Buongiorno’s Mathematical Model

2014

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“…Indeed, Schmidt et al showed that the temperature gradient mainly takes place over a fraction of the DPF cross‐section. Wu et al also showed that soot particles travelling through this region make up 27.4 % of the total number of particles (this fraction was deduced from the results reported in Figures of their article for 1000‐ and 100‐nm particles). In our work, for the largest flow velocity (Figure c), the data showed that 25.5 % of the total number of soot particles entering the filter are large enough (

D_{p} > 0.2 μ

m) to be affected by thermophoresis.…”

Section: Resultsmentioning

confidence: 92%

Numerical investigation of the impact of thermophoresis on the capture efficiency of diesel particulate filters

et al. 2016

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The present study investigates the impact of thermophoresis on soot capture in the clean cordierite porous wall of a diesel particulate filter (DPF). A three-step numerical model was developed, consisting of: (1) numerically reconstructing a representative volume of the cordierite porous wall, (2) computing gas flow through the porous wall using the lattice Boltzmann method, and (3) predicting of the DPF capture efficiency based on the time-dependent solution of a modified Langevin equation that takes thermophoresis into account. The validity of the approach was verified by carefully comparing the permeability predictions of a reconstructed cordierite porous wall to data from the literature. The impact of the magnitude and orientation of the thermophoretic force on the capture of soot particles of various sizes under different flow conditions was investigated. The thermophoretic force applied in or against the flow direction significantly affected the particle capture for the highest particle sizes and flow velocity investigated. Our results suggested that thermophoresis can potentially affect soot deposition uniformity in DPFs. Since the thermophoretic force mainly impacted soot capture efficiency in the presence of particle and flow inertia, a dimensionless criterion defined as the product of Stokes and Reynolds numbers is proposed to predict the onset of what can be called thermophoresis-enhanced inertial impaction. While similar results have been reported by others using simple flow geometries, this is the first time, to our knowledge, that this phenomenon is reported for a complex cordierite porous wall.

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“…Basically, the porous matrix will work as a filter for nanoparticles. This situation has been very well described, explained, and modeled in the recent papers by Wu et al [18,19]. The physical situation described in shows that the work on porous media filled by nanofluids are not just a mathematical exercise, but are based on deep physical understanding of nanofluid flows.…”

Section: Introductionmentioning

confidence: 85%

Fem Simulation of Triple Diffusive Natural Convection Along Inclined Plate in Porous Medium: Prescribed Surface Heat, Solute and Nanoparticles Flux

Goyal

Bhargava

2017

International Journal of Applied Mechanics and Engineering

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In this paper, triple diffusive natural convection under Darcy flow over an inclined plate embedded in a porous medium saturated with a binary base fluid containing nanoparticles and two salts is studied. The model used for the nanofluid is the one which incorporates the effects of Brownian motion and thermophoresis. In addition, the thermal energy equations include regular diffusion and cross-diffusion terms. The vertical surface has the heat, mass and nanoparticle fluxes each prescribed as a power law function of the distance along the wall. The boundary layer equations are transformed into a set of ordinary differential equations with the help of group theory transformations. A wide range of parameter values are chosen to bring out the effect of buoyancy ratio, regular Lewis number and modified Dufour parameters of both salts and nanofluid parameters with varying angle of inclinations. The effects of parameters on the velocity, temperature, solutal and nanoparticles volume fraction profiles, as well as on the important parameters of heat and mass transfer, i.e., the reduced Nusselt, regular and nanofluid Sherwood numbers, are discussed. Such problems find application in extrusion of metals, polymers and ceramics, production of plastic films, insulation of wires and liquid packaging.

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Distribution characteristics of exhaust gases and soot particles in a wall-flow ceramics filter

Cited by 34 publications

References 29 publications

Natural Convection in a Square Porous Cavity with Sinusoidal Temperature Distributions on Both Side Walls Filled with a Nanofluid: Buongiorno’s Mathematical Model

Natural Convection in a Square Porous Cavity with Sinusoidal Temperature Distributions on Both Side Walls Filled with a Nanofluid: Buongiorno’s Mathematical Model

Numerical investigation of the impact of thermophoresis on the capture efficiency of diesel particulate filters

Fem Simulation of Triple Diffusive Natural Convection Along Inclined Plate in Porous Medium: Prescribed Surface Heat, Solute and Nanoparticles Flux

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