Deformation and migration in shear-driven flows

Figure caption: Deformation/breakup of bubbles in turbulence characterized by (a) the Weber number based on small-scale turbulence (𝑊𝑒𝑡) versus large-scale persistent forcing measured by either shear (𝑊𝑒𝒮) or buoyancy (𝐸𝑜), and (b) the Ohnesorge number (𝑂ℎ) in relation to the size of the bubbles (𝐷) over the Kolmogorov scale (𝜂). The three question marks indicate the parameter space of interest.

The deformation and fragmentation of bubbles and droplets in turbulent environments lead to dispersed multiphase flows across a wide range of length scales, from nanoemulsions formed during homogenisation processes to millimeter-sized bubble clouds created by breaking ocean waves.

This study proposes investigating this phenomenon in homogeneous turbulent shear flow, where uniform shear and turbulence are present throughout the system. This approach allows for a systematic analysis of the effects of controlled mean shear on bubble breakup across different viscosity ratios.

The insights gained will serve as stepping stones toward understanding fragmentation dynamics in more complex shear flows. Ultimately, the goal is to uncover the interplay between turbulence and mean shear in determining bubble/droplet breakup pathways and resulting size distributions in inhomogeneous anisotropic systems.

FUNDING

Tec 21

Johns Hopkins University