Air-water-sand three-phase jets in crossflow, Part I: Distributions of bubble size, gas void fraction, and sand concentration

Many natural and man-made processes such as subsea blowouts entail an ejection of a complex mixture of gas-liquid-solid into a flowing ambient, resulting in the formation of three-phase jets in cross-currents. This study is the first of its kind to explore air-water-sand three-phase jets in crossflowing water by conducting a series of physical experiments. Leveraging image processing techniques, the focus is on the distributions of bubble size, gas void fraction, and sand concentration. Our results reveal that sand particles that tend to separate from the bubbly region enhance downstream bubble dispersion. In the studied scenarios, the Sauter mean diameter of bubbles is mainly affected by the initial gas and slurry (liquid-solid-mixture) flow rates. The sand concentration in the bubbly region increases with the slurry flow rate but decreases with the gas flow rate. Furthermore, the sand concentration at the same level as the nozzle exit typically follows a parabolic distribution in the streamwise direction, and the peak position shifts closer to the source with an increased gas flow rate or reduced slurry flow rate. Finally, dimensionless empirical equations are proposed for the gas void fraction and sand concentration, which agree well with the experimental data (R2 = 0.91–0.94).