scholarly journals Large particle segregation in two-dimensional sheared granular flows

2021 ◽  
Vol 6 (5) ◽  
Author(s):  
Tomás Trewhela ◽  
J. M. N. T. Gray ◽  
Christophe Ancey
Keyword(s):  
Large Particle ◽  
Granular Flows ◽  
Two Dimensional ◽  
Particle Segregation

Heat Transfer in Large Particle Bubbling Fluidized Beds

1984 ◽  
Vol 106 (1) ◽  
pp. 85-90 ◽  
Author(s):  
R. L. Adams
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Residence Time ◽  
Large Particle ◽  
Fluidized Beds ◽  
Horizontal Tube ◽  
Two Dimensional ◽  
Phase Contact ◽  
Emulsion Phase ◽  
Bubble Phase

The potential use of fluidized bed combustion of coal as a means of meeting air quality standards with high-sulfur fuels has motivated the development of theoretical models of heat transfer in large particle gas fluidized beds. Models of the separate contributions of emulsion and bubble phase heat transfer have been developed by Adams and Welty [1] and Adams [2, 3, 4] and have been substantiated by experimental data for a horizontal tube immersed in a two-dimensional cold bed obtained by Catipovic [5, 6]. The consolidation of these models to predict local and overall time-average heat transfer to immersed surfaces requires information regarding emulsion phase residence time and bubble phase contact fraction for the particular geometry of interest. The analytical procedure to consolidate these models is outlined in the present work, then applied to the case of a horizontal tube immersed in a two-dimensional atmospheric pressure cold bed. Measurements of emulsion phase residence time and bubble phase contact fraction obtained by Catipovic [5] are used in the calculations for particle diameters ranging from 1.3 to 6 mm. The results agree favorably with experimental data and further substantiate the fundamental assumptions of the model.

Large-scale flume modelling of segregation processes in debris flows

2020 ◽  
Author(s):  
Julia Kimball ◽  
W Andrew Take
Keyword(s):  
Debris Flows ◽  
Large Scale ◽  
Multicomponent Mixture ◽  
Granular Flows ◽  
Particle Sizes ◽  
Deposit Morphology ◽  
Multicomponent Mixtures ◽  
Particle Segregation ◽  
Experimental Strategies ◽  
Landslide Deposit

<p>Debris flows are powerful natural hazards posing risk to life, infrastructure, and property.  Understanding the particle scale interactions in these flows is a key component in the development of models to predict the mobility, distal reach, and hazard posed by a given event. In this study we focus on the process of segregation in debris flows, using a large-scale landslide flume to explore segregation in mixtures of 25 mm, 12 mm, 6 mm, and 3 mm diameter particle sizes. Sample volumes, consisting of a multicomponent mixture of materials, up to 1 m<sup>3</sup> in size are released at the top of a 6.8 m long, 2.1 m wide slope, inclined at 30 degrees to the horizontal to initiate flow. Subsequent analysis is completed to determine the extent of vertical and longitudinal segregation of the post-landslide deposit morphology. A range of experimental strategies are explored to provide quantitative measures of particle segregation. Particle size is identified via image analysis and various techniques are applied for the longitudinal sectioning of the deposit, using measurements of segregation at the sidewall of the transparent flume, contrasted with planes measured from within the centre of the deposit. Further, replicate experiments are shown to quantify the probabilistic variation in segregation for multicomponent mixtures of dry granular flows, as well as initially saturated granular flows, to explore the effect of pore fluid on segregation processes.</p>

Coupling of full two-dimensional and depth-averaged models for granular flows

2013 ◽  
Vol 201 ◽  
pp. 56-68 ◽  
Author(s):  
Birte Domnik ◽  
Shiva P. Pudasaini ◽  
Rolf Katzenbach ◽  
Stephen A. Miller
Keyword(s):  
Granular Flows ◽  
Two Dimensional ◽  
Averaged Models

scholarly journals Large particle segregation, transport and accumulation in granular free-surface flows – ERRATUM

2010 ◽  
Vol 657 ◽  
pp. 539-539 ◽  
Author(s):  
J. M. N. T. GRAY ◽  
B. P. KOKELAAR
Keyword(s):  
Free Surface ◽  
Large Particle ◽  
Free Surface Flows ◽  
Particle Segregation ◽  
Surface Flows

The Publishers apologise to the authors and readers for the following errors which occurred in Gray & Kokelaar (2010).

Geophysical granular and particle-laden flows: review of the field

2005 ◽  
Vol 363 (1832) ◽  
pp. 1497-1505 ◽  
Author(s):  
Kolumban Hutter
Keyword(s):  
Turbulent Flows ◽  
Granular Flows ◽  
Gravity Currents ◽  
Two Dimensional ◽  
Theme Issue ◽  
Aeolian Transport ◽  
Particle Laden Flows ◽  
Granular Base ◽  
Sand Dust ◽  
Dimensional Surface

An introduction is given to the title theme, in general, and the specific topics treated in detail in the articles of this theme issue of the Philosophical Transactions . They fit into the following broader subjects: (i) dense, dry and wet granular flows as avalanche and debris flow events, (ii) air-borne particle-laden turbulent flows in air over a granular base as exemplified in gravity currents, aeolian transport of sand, dust and snow and (iii) transport of a granular mass on a two-dimensional surface in ripple formations of estuaries and rivers and the motion of sea ice.

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