Incipient motion of a small particle in the viscous boundary layer at a pipe wall

Experimental Study of Low Concentration Sand Transport in Multiphase Air–Water Horizontal Pipelines

“…The effect of particle Vsg (m/s) shape on drag force may also contribute in this observation. It is worth noting that the effect of particle shape has been observed in previous studies and confirms our observation in the current study [56]. More detailed investigation of particle shape is needed to quantify this effect.…”

Impact of continuous particle size distribution width and particle sphericity on minimum pickup velocity in gas–solid pneumatic conveying

“…Studies on pneumatic conveying systems span characterization of pneumatic flow into various flow modes and its dependence on material properties (Pan, 1999), analysis of axial and radial swirling (Li and Tomita, 2000), transport limitations (Wypych and Yi, 2003), simulations involving shear rate (Stevenson et al, 2002), and comparison of the aptitude of various models (namely, Eulerian, Lagrangian and hybrid) in simulating pneumatic conveying (Pirker et al, 2010). The focus of this work is on the minimum pickup velocity (U pu ), which is defined as the gas velocity required to initiate the rolling motion of (Hallow, 1973) or suspend (Kalman et al, 2005) the particle initially at rest on a surface.…”

Selection of the Optimal Critical Velocity for Sand Transport at Low Concentrations for Near-Horizontal Flow

“…Our database contains 478 sand transport data for gas/solid flow and 161 sand transport data for liquid/solid flow, for a total of 639 data points, all of which were obtained from open literature [1,2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], where the authors who conducted the studies were interested in quantifying the sand transport velocity for different sets of operating conditions. In addition, for the velocity predictions, 40 sand transport models were considered, and similar to the sand transport data, the models are also publicly available from the literature [1-4, 7, 9-11, 18, 20-47], and the models were developed to predict the velocity required for transporting solids given an operating condition.…”

“…Sand transport models are used to predict the critical velocity, defined as the required "fluid velocity for particle motion" [1], in order for the fluid to be able to transport the sand particles in the pipe. The transport of the sand particle must take place in order to prevent the accumulation of sand particles, which is of importance, as the accumulation of sand particles in pipes can have consequences, such as blockage in the pipeline [2], the prevention of corrosion inhibitors from reaching the bottom of the pipe [3], and erosion due to the decreased flow area in the pipe [4].…”