Measuring Lagrangian accelerations using an instrumented particle

TL;DR

This paper introduces an innovative instrumented particle that transmits acceleration data in real-time, enabling flow characterization in opaque or granular fluids where optical methods are ineffective.

Contribution

The study presents a novel, wireless, adjustable-density particle for measuring accelerations in various fluids, suitable for industrial and scientific flow analysis.

Findings

Accurately measures accelerations in turbulent flows

Compatible with opaque and granular fluids

Provides real-time flow data transmission

Abstract

Accessing and characterizing a flow impose a number of constraints on the employed measurement techniques; in particular optical methods require transparent fluids and windows in the vessel. Whereas one can adapt apparatus, fluid and methods in the lab to these constraints, this is hardly possible for industrial mixers. We present in this article a novel measurement technique which is suitable for opaque or granular flows: an instrumented particle, which continuously transmits the force/acceleration acting on it as it is advected in a flow. Its density is adjustable for a wide range of fluids and because of its small size and its wireless data transmission, the system can be used both in industrial and scientific mixers allowing a better understanding of the flow within. We demonstrate the capabilities and precision of the particle by comparing its transmitted acceleration to alternative measurements, in particular in the case of a turbulent von K\'arm\'an flow. Our technique shows to be an efficient and fast tool to characterize flows.