How jets of air, water, and sand transport materials through bodies of water
DOI: 10.1063/10.0043827
How jets of air, water, and sand transport materials through bodies of water lead image
Subsea blowouts, dredging operations, and deep-sea mining release solids, liquids, and gases into moving water. How particles spread and settle in these situations can have large environmental effects, especially when pollutants like oil droplets are involved.
Most studies focus on only one or two of these materials. To better model real-world situations, Zhang et al. simulated injecting a jet of air, water, and sand into moving water.
“One of the main objectives of this study is to directly observe how the three phases interact and evolve together by resolving the flow in detail, providing a clearer understanding of the overall flow behavior,” said author Huan Zhang. “This, in turn, allows us to better understand how sand influences the behavior of both the water and air, as well as how it is transported and ultimately settles.”
Their simulations showed that air and sand tend to work in competitive directions: The bubbles lift the flow of the jet upward, while sand particles weigh and slow the flow down. However, the sand has a much larger effect on the flow than the air, even at significantly lower concentrations.
They also found the way the sand spreads is not random. In general, a jet interacting with a fluid crossflow leads to several large-scale vortex structures, including two vortices that make up a counter-rotating vortex pair. According to the researchers’ simulations, this vortex pair governs how the sand disperses, falls, and settles.
The group plans to extend their simulations to higher bubble and sand concentrations, where the interactions will be even stronger. They will also incorporate more realistic conditions, such as stratified water and wave-current interactions.
“Ultimately, we aim to develop predictive tools that can help better understand and manage multiphase flows in real-world engineering and environmental applications,” Zhang said.
Source: “Three-phase large eddy simulation of air-water-sand jets in crossflow,” by Huan Zhang, David Zhu, Dongfang Liang, Jun Qiu, Yu Qian, and Wenming Zhang, Physics of Fluids (2026). The article can be accessed at https://doi.org/10.1063/5.0324567 .
