Experimental and Computational Studies of Gravity-Driven Dense Granular Flows PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Experimental and Computational Studies of Gravity-Driven Dense Granular Flows PDF full book. Access full book title Experimental and Computational Studies of Gravity-Driven Dense Granular Flows by Yesaswi Narendra Chilamkurti. Download full books in PDF and EPUB format.
Author: Yesaswi Narendra Chilamkurti
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Get Book Here
Book Description
Author: Yesaswi Narendra Chilamkurti
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4
Get Book Here
Book Description
The authors report and analyze the results of numerical studies of dense granular flows in two and three dimensions, using both linear damped springs and Hertzian force laws between particles. Chute flow generically produces a constant density profile that satisfies scaling relations suggestive of a Bagnold grain inertia regime. The type for force law has little impact on the behavior of the system. Failure is not initiated at the surface, consistent with the absence of surface flows and different principal stress directions at vs. below the surface.
Author:
Publisher:
ISBN:
Category : Condensed matter
Languages : en
Pages : 34
Get Book Here
Book Description
Author: Luoyilang Ke
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Recently, applying mesh free method coupled with a constitutive rheology has achieved success in modeling dynamics in dry granular flows. However, research on comprehensive validation on the coupled model in different aspects, such as pressure, velocity, shear stress, surface, friction factor and different geometries is limited. In this study, three different cases, including gravity driven flow, 2D column collapse and granular dam-break are simulated to validate the coupled model of MPS method with (I) rheology model, by comparing the simulated results with analytical solutions and experimental results. In the simulations, flow characteristics are successfully captured in dry granular flows in different flow scenarios. In gravity driven flow, MPS reproduces a steady uniform zone in which good agreements have been achieved in terms of pressure, shear stress, friction factor and velocity distribution comparing numerical results with analytical solutions. In 2D column collapse and granular dam-break flow, the MPS has good performance in capturing dynamic features observed and measured in labs. After validation of the coupled model, numerical results pressure, tangential stress and friction factor are analyzed and discussed. It is found that the coupled model can be used to distinguish flow regimes in granular flows according to calculated pressure, stress, and friction factor. In numerical results, non-linear distributions with an obvious change on the free surface for the pressure and stress are observed. This study lays solid examples to show that the MPS method coupled with rheology model is a useful numerical tool to reflect flow characteristics in granular flows. Keywords: MPS, granular flow, rheology model, stress, friction factor.
Author: Kevin Facto
Publisher:
ISBN:
Category : Granular materials
Languages : en
Pages : 101
Get Book Here
Book Description
This dissertation presents experiments that studied two gravity driven granular channel flows. The first experiment used magnetic resonance imaging to measure the density and displacement distributions of poppy seeds flowing in a rough walled channel. Time-averaged measurements of normalized velocity and density showed little flow speed dependence. Instantaneous measurements, however, showed marked velocity dependence in the displacement distributions. There was evidence of aperiodic starting and stopping at lower flow speeds and the onset of density waves on a continuous flow at higher speeds. The second experiment measured forces in all three spatial directions at the boundary of a flow of steel balls. The relationship between the normal and the tangential forces were examined statistically and compared to the Coulomb friction model. For both large and small forces, the tangential and normal forces are unrelated, as there appears to be a strong tendency for the tangential force to maintain a value that will bear the weight the weight of the particles in flow.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Get Book Here
Book Description
Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. Its goal is to understand the regime of inclined flow that involves a large, relatively passive mass of granular material moving above a narrow region of intensely sheared, colliding grains. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the presetn reporting period, we have completed a series of experiments to measure the collision properties of various small particles. Results for 3mm glass beads are presented here. In addition, we have made progress in the design of a new sensor to measure simultaneously the particle volume fraction near the wall and the normal force of impact from individual collisions. Finally, we have conducted additional simulations of the rapid granular flows of spheres interacting with a flat, frictional wall. The objective was to generate semi-empirical expressions for the boundary conditions imposed by the wall on the flow.
Author: Joseph Jeremiah Estep
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages :
Get Book Here
Book Description
Granular materials are composed of solid, discrete particles and exhibit mechanical behavior that differs from those of fluids and solids. The rheology of granular flows is principal to a suite of natural hazards. Laboratory experiments and numerical models have adequately reproduced several features observed in terrestrial gravity driven geophysical flows; however, quantitative comparison to field observations exposes a failure to explain the high mobility and duration of many of these flows. The ability of a granular material to resist deformation is a function of the force chain network inherent to the material. This investigation addresses the evolutionary character of force chains in unconfined, two-dimensional, gravity driven granular flows. Our particular emphasis concerns the effects of stress localization on the substrate by dynamic force chain evolution and the implications for bed erosion in dense granular flows. Experimental systems employing photoelastic techniques provide an avenue for quantitative force analysis via image processing and provide dataset that can be used validate discrete element modeling approaches. We show that force chains cause extreme bed force localization throughout dynamic granular systems in spatial and temporal space; and that these localized forces can propagate extensively into the substrate, even ahead of the flow front.
Author: Brian E. Sanders
Publisher:
ISBN:
Category : Fluid mechanics
Languages : en
Pages : 322
Get Book Here
Book Description
Author: John J. Drozd
Publisher:
ISBN:
Category :
Languages : en
Pages : 258
Get Book Here
Book Description
Author: V. Middleton
Publisher: Springer
ISBN: 1402008724
Category : Science
Languages : en
Pages : 928
Get Book Here
Book Description
This comprehensive, one-volume encyclopedia covers the sedimentological aspects of sediments and sedimentary rocks. It features more than 250 entries by some 180 eminent contributors from all over the world, excellent indices, cross references, and extensive bibliographies.
