1. Air Injection Into Water‐Saturated Granular Media—A Dimensional Meta‐Analysis.
- Author
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Ben‐Noah, Ilan, Friedman, Shmulik P., and Berkowitz, Brian
- Subjects
BUOYANCY ,PROPERTIES of fluids ,FLOW velocity ,AIR flow ,VISCOSITY ,GRANULAR materials - Abstract
Gas saturation degree and flow patterns are key factors for modeling and designing multiphase systems and operations. In turn, these factors are strongly related to the flow dynamics, which are controlled largely by the fluid and media properties. However, predicting the gas distribution and flow pattern remains elusive. Data from 11 series of steady air injection experiments into initially water‐saturated granular media, conducted with different media and flow geometries, are analyzed to identify the main factors governing air saturation and flow patterns. For air injection into otherwise water‐saturated granular media, the flow pattern is affected mainly by the ratio between the Capillary number (ratio of viscous to capillary forces) and the Bond number (ratio of gravitational to capillary forces), that is, by the ratio of viscous to gravitational forces. Moreover, the meta‐analysis presented here indicates that the steady air saturation degree is correlated strongly to flow velocity and grain diameter. Furthermore, analysis of experimental results from different studies of air injection into coarse, homogeneous, granular media (glass beads, sand) also suggests a significant effect of inertial forces. Both viscous and buoyancy forces increased air saturation, while capillary forces decreased the saturation degree. The ratio between capillary and buoyancy forces determines the air flow pattern during air injection into otherwise water‐saturated media. Key Points: Capillary, viscous, gravity, and inertial forces control air flow regime and content, the latter increases with velocity and grain sizeA new phase diagram depicts the effect of Ca and Bo on air flow patternsThe effect of the background saturation degree cannot be easily decoupled from the Bo‐Ca‐flow pattern phase diagram [ABSTRACT FROM AUTHOR]
- Published
- 2022
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