Abrupt growth of large aggregates by correlated coalescences in turbulent flow

TL;DR

This paper reveals that in turbulent flows, large aggregates form abruptly due to correlated coalescence events, challenging traditional coagulation models and impacting processes like planet formation and rain.

Contribution

It demonstrates the failure of Smoluchowski's coagulation kinetics in turbulent conditions and introduces a new understanding of rapid large aggregate formation through correlated violent events.

Findings

Large aggregates form abruptly in turbulent flows

Correlated violent events accelerate coalescence

Significant corrections to classical coagulation models

Abstract

Smoluchowski's coagulation kinetics is here shown to fail when the coalescing species are dilute and transported by a turbulent flow. The intermittent Lagrangian motion involves correlated violent events that lead to an unexpected rapid occurrence of the largest particles. This new phenomena is here quantified in terms of the anomalous scaling of turbulent three-point motion, leading to significant corrections in macroscopic processes that are critically sensitive to the early-stage emergence of large embryonic aggregates, as in planet formation or rain precipitation.