scholarly journals Simulating dense granular flow using the μ ( I )‐rheology within a space‐time framework

Author(s):  
Linda Gesenhues ◽  
Marek Behr
Author(s):  
Alessandro Tasora ◽  
Mihai Anitescu

Aiming at the simulation of dense granular flows, we propose and test a numerical method based on successive convex complementarity problems. This approach originates from a multibody description of the granular flow: all the particles are simulated as rigid bodies with arbitrary shapes and frictional contacts. Unlike the discrete element method (DEM), the proposed approach does not require small integration time steps typical of stiff particle interaction; this fact, together with the development of optimized algorithms that can run also on parallel computing architectures, allows an efficient application of the proposed methodology to granular flows with a large number of particles. We present an application to the analysis of the refueling flow in pebble-bed nuclear reactors. Extensive validation of our method against both DEM and physical experiments results indicates that essential collective characteristics of dense granular flow are accurately predicted.


2012 ◽  
Vol 220 ◽  
pp. 7-14 ◽  
Author(s):  
V. Vidyapati ◽  
M. Kheiripour Langroudi ◽  
J. Sun ◽  
S. Sundaresan ◽  
G.I. Tardos ◽  
...  

2018 ◽  
Vol 30 (7) ◽  
pp. 073302 ◽  
Author(s):  
J. D. Goddard ◽  
J. Lee

2012 ◽  
Vol 565 ◽  
pp. 278-283 ◽  
Author(s):  
Stephen Wan ◽  
Takashi Sato ◽  
Andry Hartawan

We report preliminary results from an on-going study investigating the effect of fixing workpieces within the media flow field contained in a typical vibratory finishing bowl. To this end, we studied the surface roughness evolution over the surfaces of workpieces with generic geometries such as cylinders. A granular flow dynamics model applicable to dense granular flow and a previously derived process equation were invoked in order to respectively describe the flow of the abrasive media; and the roughness distribution in terms of the granular pressure and velocity. By solving the granular flow field for the pressure and velocity distribution on a given geometry using a general purpose computational fluid dynamics (CFD) code, we were able to analyse changes in surface roughness distribution from the process equation. The immobilized cylinders were submerged in the top portion of the media flow field so as to facilitate comparison between media flow past the workpieces as experimentally observed and as predicted by the CFD simulations. We conclude with an analysis, based on both experimental and predicted results, of the way in which media flow direction biases the surface roughness distribution on an immobilized cylinder.


2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Ziyang Zhao ◽  
Jun Zhang

From the microperspective, this paper presents a model based on a new type of noncontinuous theoretical mechanical method, molecular dynamics (MD), to simulate the typical soil granular flow. The Hertzian friction formula and viscous damping force are introduced in the MD governing equations to model the granular flow. To show the validity of the proposed approach, a benchmark problem of 2D viscous material flow is simulated. The calculated final flow runout distance of the viscous material agrees well with the result of constrained interpolated profile (CIP) method as reported in the literature. Numerical modeling of the propagation of the collapse of three-dimensional axisymmetric sand columns is performed by the application of MD models. Comparison of the MD computational runout distance and the obtained distance by experiment shows a high degree of similarity. This indicates that the proposed MD model can accurately represent the evolution of the granular flow. The model developed may thus find applications in various problems involving dense granular flow and large deformations, such as landslides and debris flow. It provides a means for predicting fluidization characteristics of soil large deformation flow disasters and for identification and design of appropriate protective measures.


2010 ◽  
Vol 32 (4) ◽  
pp. 333-338 ◽  
Author(s):  
R. Blumenfeld ◽  
S. F. Edwards ◽  
M. Schwartz

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