Investigation of transient sheet/cloud cavitating flow dynamics from multiscale perspective

Sheet/cloud cavitation usually leads to a wide range of length scales in both turbulence and phase distribution from microbubbles cavity advection. In the present work, Eulerian–Lagrangian multiscale model with two-way coupling is utilized simulate cavitating flow around (National Advisory Committee for Aeronautics) NACA66 hydrofoil at an incidence angle 8° number σ = 1.4. The can simultaneously capture large-scale cavities microscale bubbles. features are good agreement experimental observations containing not only periodical formation, growth, detachment, advection cavities, but also thousands cavities. results show that overall evolution frequency about 45 Hz. Meanwhile, dynamic mode decomposition method identify coherent spatial temporal sheet/cloud flow, which indicates complex vortices various dominate corresponding scale, vapor structure decreases increasing scale Under effect turbulence, break into microbubbles, causing size discrete bubbles increase rapidly re-entrant jet cloud shedding regions. Additionally, bubble-size spectrum time-averaged period has two regimes. For larger bubbles, bubble density proportional radius power −10/3. smaller exhibits −4/3 power-law scaling.