Dabao Li | Searcharxiv

arXiv2026

K41 Scaling in Bubble-Induced Turbulence Arises from Single-Bubble Wakes

We use high-resolution, interface-resolved direct numerical simulations (DNS) to investigate the origin of Kolmogorov (K41) scaling in bubble-induced turbulence (BIT). Region-wise velocity structure functions show that the 2/3 scaling appears only within bubble wake regions. Comparison with matched single-bubble DNS further indicates that the K41 scaling observed in the full BIT field arises from the superposition of individual bubble wakes. On this basis, we derive a scaling for the dissipation rate in dilute BIT that is consistent with experimental results from the literature.

physics.flu-dyn↗

arXiv2025

Rising bubbles draw surface patterns: a numerical study

Small bubbles rising in a chain can self-organize into regular patterns upon reaching a liquid's free surface. This phenomenon is investigated through direct numerical simulations. By varying the bubble release period, distinct branching patterns characterized by different numbers of arms are observed. These macroscopic regular configurations arise from localized non-contact repulsion and pair collisions between bubbles as they arrive at the free-surface emergence site. A theoretical model is proposed to quantitatively relate the number of branches to the bubble release period. The model also predicts probabilities of observing specific arm counts in reality. This study provides insights into broader nonlinear pattern formation and self-organization phenomena.

physics.flu-dyn↗