CAREER: Multiscale experimental framework on dynamics of deformable particles in turbulent dispersed multiphase flow

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From rain droplets in clouds to gas bubbles in bioreactors and nuclear reactors, multiphase flows occurring in nature and industrial applications are often turbulent, spanning a wide range of length and time scales and posing significant challenges to numerical and experimental methods. Significant progress has been made in characterizing the turbulent multiphase flow dispersed with spherical particles; much less is known, however, about another large category with dispersed phase consisting of deformable liquid drops or gas bubbles. Those particles can freely deform, tumble, break up and coalesce in turbulent flow, adding new degrees of freedom to an already complex problem. The key questions arise as to what are the statistics of unique dynamics of these deformable particles and how to characterize their complex couplings with the carrier phase. In order to address those questions and gain insights in the full physical picture of the dynamics of deformable particles, the project involves a multiscale experimental framework on several different length scales from interface dynamics to large-scale statistics. In order to obtain couplings of two phases, both the carrier phase and the dispersed phases will be tracked in the Lagrangian framework simultaneously. This enables us to measure, not only the velocity of both phases, but also those high-order derivatives, including acceleration and velocity gradient tensor, that are more important to the momentum couplings between two phases.