<< When swarms of bubbles are driven upwards through a fluid by their buoyancy, they can generate complex flow patterns in their wake. Named 'pseudo-turbulence,' these patterns are characterized by a universal mathematical relationship between the energy of flows of different sizes, and the frequency of their occurrence. This relationship has now been widely observed through 3-D simulations, but it is less clear whether it would still hold for 2-D swarms of bubbles. >>
AA << show that in 2-D simulated fluids, this pattern changes within larger-scale flows in less viscous fluids. (..) In the past, many studies of pseudo-turbulence have found the statistical properties of 3-D bubble swarms remain universal over a wide range of bubble surface tensions, fluid viscosities, and density ratios between bubbles and fluids. In 2-D fluids, however, an effect named an 'inverse energy cascade' enables energy to be transferred from small- to large-scale flows. >>
Characterising complex flows in 2-D bubble swarms. Springer. Dec 4, 2020
Rashmi Ramadugu, Vikash Pandey, Prasad Perlekar. Pseudo-turbulence in two-dimensional buoyancy-driven bubbly flows: A DNS study. The European Physical Journal E. V 43, no. 73. doi: 10.1140/ epje/i2020-11997-0. Nov 25, 2020.
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