Study on liquid turbulence modulation by microbubbles in different turbulence layers

Bubbly flows exist extensively in industrial processes. To enhance efficiencies of industrial processes, it is very necessary and important to understand detailedly mechanisms of liquid turbulence modulation by bubbles. To understand mechanisms of the liquid turbulence modulation by microbubbles, an Euler-Lagrange two-way model was used to investigate and analyze deeply the liquid turbulence modulation by microbubbles in the subviscous, buffer, and outer layers, respectively. The present results show that the liquid turbulence modulation by microbubbles is related to microbubble locations; the liquid turbulence is intensified when microbubbles are in the outer layers, whereas the liquid turbulence is suppressed when microbubbles are in the subviscous and buffer layer; and the drag reduction occurs only when microbubbles are in the buffer layer.