Drag Reduction by Microbubbles in Turbulent Flows: the Limit of Minute Bubbles

Abstract

Drag reduction by microbubbles is a promising engineering method for improving ship performance. A fundamental theory of the phenomenon is lacking however, making actual design quite uphazard. We offer here a theory of drag reduction by microbubbles in the limit of very small bubbles, when the effect of the bubbles is mainly to normalize the density and the viscosity of the carrier fluid. The theory culminates with a prediction of the degree of drag reduction given the concentration profile of the bubbles. Comparisons with experiments are discussed and the road ahead is sketched.

4 pages, 2 figs., included, PRL submitted

References in corpus (3)

• Drag Reduction by Polymers in Wall Bounded Turbulence
• The clustering instability of inertial particles spatial distribution in turbulent flows
• Saturation of Turbulent Drag Reduction in Dilute Polymer Solutions

Cited by in corpus (9)

• Colloquium: Theory of Drag Reduction by Polymers in Wall Bounded Turbulence
• Bubble drag reduction requires large bubbles
• Microbubbly drag reduction in Taylor-Couette flow in the wavy vortex regime
• Physical mechanisms governing drag reduction in turbulent Taylor-Couette flow with finite-size deformable bubbles
• Drag reduction in numerical two-phase Taylor-Couette turbulence using an Euler-Lagrange approach
• Binary-Fluid Turbulence: Signatures of Multifractal Droplet Dynamics and Dissipation Reduction
• Drag Reduction by Bubble Oscillations
• Phenomenology of Wall Bounded Newtonian Turbulence
• Turbulent drag reduction in magnetohydrodynamic and quasi-static magnetohydrodynamic turbulence