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Title: Normal stress effects in the gravity driven flow of granular materials

Authors:
; ; ;
Publication Date:
Research Org.:
National Energy Technology Lab. (NETL), Pittsburgh, PA, and Morgantown, WV (United States). In-house Research
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1393412
Report Number(s):
A-UNIV-PUB-134
Journal ID: ISSN 0020-7462; PII: S0020746217300628
DOE Contract Number:
DE-FE0004000
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Non-Linear Mechanics; Journal Volume: 92; Journal Issue: C
Country of Publication:
United States
Language:
English
Subject:
Granular materials; Normal-stress effects; Maximum packing; Shear-thinning fluid; Second grade fluids; Continuum mechanics

Citation Formats

Wu, Wei-Tao, Aubry, Nadine, Antaki, James F., and Massoudi, Mehrdad. Normal stress effects in the gravity driven flow of granular materials. United States: N. p., 2017. Web. doi:10.1016/j.ijnonlinmec.2017.03.016.
Wu, Wei-Tao, Aubry, Nadine, Antaki, James F., & Massoudi, Mehrdad. Normal stress effects in the gravity driven flow of granular materials. United States. doi:10.1016/j.ijnonlinmec.2017.03.016.
Wu, Wei-Tao, Aubry, Nadine, Antaki, James F., and Massoudi, Mehrdad. Thu . "Normal stress effects in the gravity driven flow of granular materials". United States. doi:10.1016/j.ijnonlinmec.2017.03.016.
@article{osti_1393412,
title = {Normal stress effects in the gravity driven flow of granular materials},
author = {Wu, Wei-Tao and Aubry, Nadine and Antaki, James F. and Massoudi, Mehrdad},
abstractNote = {},
doi = {10.1016/j.ijnonlinmec.2017.03.016},
journal = {International Journal of Non-Linear Mechanics},
number = C,
volume = 92,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}
  • An approximate solution is presented to the problem of calculating the flow of a cohesionless granular material in a conical hopper such as that used in some coal gasifiers. Treating the material as a perfectly plastic continuum (thus satisfying the Mohr-Coulomb yield condition), the model describes the behavior of granular material in fairly good agreement with experimental data. Intended for application to a mass-flow hopper only, the model is most effective on hoppers with small hopper angles. The model and experimental results deviate at large hopper angles.
  • Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, the authors formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes do not influence effective stresses. They implement the model using two finite element codes. As an illustrative case, they calculate the groundwater flow field, total body force field, and effective stress field in a straight, homogeneous hillslope. The total bodymore » force and effective stress fields show that groundwater flow can influence shear stresses as well as effective normal stresses. In most parts of the hillslope, groundwater flow significantly increases the Coulomb failure potential {Phi}, which we define as the ratio of maximum shear stress to mean effective normal stress. Groundwater flow also shifts the locus of greatest failure potential toward the slope toe. However, the effects of groundwater flow on failure potential are less pronounced than might be anticipated on the basis of a simpler, one-dimensional, limit equilibrium analysis. This is a consequence of continuity, compatibility, and boundary constraints on the two-dimensional flow and stress fields, and it points to important differences between our elastic continuum model and limit equilibrium models commonly used to assess slope stability.« less
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