Stirring faces: mixing in a quiescent fluid

TL;DR

This paper visualizes the mixing process caused by a sinusoidally plunging flat plate in a quiescent fluid, revealing complex flow structures and strange face patterns through Lyapunov exponent analysis.

Contribution

It introduces a novel visualization of mixing dynamics and flow structures using finite-time Lyapunov exponents in a fluid-plate interaction scenario.

Findings

Emergence of strange face patterns in flow visualization

Identification of attracting and repelling flow sets

Insights into mixing mechanisms in quiescent fluids

Abstract

This fluid dynamics video depicts the mixing that occurs as a two-dimensional flat plate plunges sinusoidally in a quiescent fluid. Finite-time Lyapunov exponents reveal sets that are attracting or repelling. As the flow field develops, strange faces emerge.