Characterizing flows with an instrumented particle measuring Lagrangian accelerations

TL;DR

This paper introduces a new Lagrangian measurement method using an instrumented particle that transmits acceleration data, enabling flow characterization especially in challenging optical conditions.

Contribution

The paper develops a novel instrumented particle and signal processing techniques to measure flow forces and identify vortex structures in Lagrangian flow analysis.

Findings

Successfully characterizes flow forces and vortex presence

Provides a robust method for long trajectory analysis

Effective in opaque or difficult optical environments

Abstract

We present in this article a novel Lagrangian measurement technique: an instrumented particle which continuously transmits the force/acceleration acting on it as it is advected in a flow. We develop signal processing methods to extract information on the flow from the acceleration signal transmitted by the particle. Notably, we are able to characterize the force acting on the particle and to identify the presence of a permanent large-scale vortex structure. Our technique provides a fast, robust and efficient tool to characterize flows, and it is particularly suited to obtain Lagrangian statistics along long trajectories or in cases where optical measurement techniques are not or hardly applicable.