Velocity and volume fraction measurements of granular flows in a steep flume

被引：0
作者：
SARNO L. [1 ,2 ]
PAPA M.N. [1 ]
CARLEO L. [1 ]
VILLANI P. [1 ,3 ]
机构：
[1] Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, Fisciano
[2] Institute of Fluid Dynamics (FDY), Technische Universität Darmstadt, Otto-Berndt-Str. 2, Darmstadt
[3] University Consortium for Research on Major Hazards (CUGRI), Salerno, Italy Via Giovanni Paolo II, 132, Fisciano
来源：
Environmental and Engineering Geoscience | 2021年 / 27卷 / 02期
关键词：
Debris Flows; Granular Flows; Particle Image Velocimetry (PIV); Rheological Stratification; Stochastic-Optical Method (SOM); Volume Fraction;
D O I：
10.2113/EEG-D-20-00027
中图分类号：
学科分类号：
摘要：
Laboratory experiments on granular flows remain essential tools for gaining insight into several aspects of granular dynamics that are inaccessible from field-scale investigations. Here, we report an experimental campaign on steady dry granular flows in a flume with inclination of 35°. Different flow rates are investigated by adjusting an inflow gate, while various kinematic boundary conditions are observed by varying the basal roughness. The flume is instrumented with high-speed cameras and a no-flicker LED lamp to get reliable particle image velocimetry measurements in terms of both time averages and second-order statistics (i.e., granular temperature). The same measuring instruments are also used to obtain concurrent estimations of the solid volume fraction at the sidewall by employing the stochastic-optical method (SOM). This innovative approach uses a measurable quantity, called two-dimensional volume fraction, which is correlated with the near-wall volume fraction and is obtainable from digital images under controlled illumination conditions. The knowledge of this quantity allows the indirect measurement of the nearwall volume fraction thanks to a stochastic transfer function previously obtained from numerical simulations of distributions of randomly dispersed spheres. The combined measurements of velocity and volume fraction allow a better understanding of the flow dynamics and reveal the superposition of different flow regimes along the flow depth, where frictional and collisional mechanisms exhibit varying relative magnitudes. © 2021 Geological Society of America. All rights reserved.
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页码：245 / 257
页数：12
相关论文
共 46 条
[11]  
Coviello V., Arattano M., Comiti F., Macconi P., Marchi L., Seismic characterization of debris flows: Insights into energy radiation and implications for warning, Journal of Geophysical Research: Earth Surface, 124, 6, pp. 1440-1463, (2019)
[12]  
Eckart W., Gray J. M. N. T., Hutter K., Particle image velocimetry (PIV) for granular avalanches on inclined planes, Dynamic response of granular and porous materials under large catastrophic deformations: Lecture notes in applied and computational mechanics, 11, pp. 195-218, (2003)
[13]  
Egashira S., Itoh T., Takeuchi H., Transition mechanism of debris flows over rigid bed to over erodible bed, Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere, 26, 2, pp. 169-174, (2001)
[14]  
MiDi G. D. R., On dense granular flows, European Physical Journal E, 14, 4, pp. 341-365, (2004)
[15]  
Hurlimann M., Coviello V., Bel C., Guo X., Berti M., Graf C., Hubl J., Miyata S., Smith J. B., Yin H.-Y., Debris-flow monitoring and warning: Review and examples, Earth-Science Reviews, 199, (2019)
[16]  
Iverson R. M., George D. L., A depth-averaged debrisflow model that includes the effects of evolving dilatancy. I. Physical basis, Proceedings of the Royal Society A, 470, 2170, (2014)
[17]  
Iverson R. M., Vallance J. W., New views of granular mass flows, Geology, 29, 2, pp. 115-118, (2001)
[18]  
Jenkins J. T., Savage S. B., A theory for rapid flow of identical, smooth, nearly elastic, spherical particles, Journal of Fluid Mechanics, 130, pp. 187-202, (1983)
[19]  
Jesuthasan N., Baliga B. R., Savage S. B., Use of particle tracking velocimetry for measurements of granular flows, Review and application: KONA Powder and Particle Journal, 24, pp. 15-26, (2006)
[20]  
Jop P., Forterre Y., Pouliquen O., Crucial role of sidewalls in granular surface flows consequences for the rheology, Journal of Fluid Mechanics, 541, pp. 167-192, (2005)
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