Interaction of Elasto-inertial Turbulence and material microstructure – INTER-ET

Introduction

Transport and handling of complex fluids is an important contributor to world energy consumption, with an estimated 10% coming from pumping suspensions. Improving their mixing and heat transfer is key for new applications ranging from the process industry to medicine.

Impact of Polymers

A tiny amount of polymers can make the fluid viscoelastic, completely changing its flow characteristics. This modification can reduce turbulent friction and pumping power by around 70% at large scales, but it also creates a whole new kind of turbulence at small scales.

Elastic Turbulence

Elastic turbulence has recently received exponentially increasing attention as a promising way to increase mixing and heat transfer at small scales, such as in lab-on-a-chip applications. It also plays a role in:

• Efficient cleaning and storage of fluids in the ground
• Undesired sources of chaotic flow paths and friction, impacting cell sorting and blood flow

Knowledge Gaps

However, significant gaps exist in understanding elastic and elasto-inertial turbulence, particularly between conflicting experiments and theories, as well as the multiscale interactions needed to sustain it.

Proposal Overview

The INTER-ET proposal aims to revolutionize the state-of-the-art understanding of elastic fluid turbulence and its interaction with material microstructure. This will be achieved through synergetic simulations and experiments that were previously impossible.

Methodology

Our high-fidelity methods will enable:

1. Three-dimensional studies of elastoviscoplastic fluid turbulence
2. Suspensions of tens of thousands of particles
3. Experimental time-resolved measurements on the microscale

Theoretical Needs

Theories for Newtonian turbulence do not hold for elastic fluids, highlighting an urgent need for improved theories and models in wall-bounded turbulence of complex fluids.

Objectives

The INTER-ET proposal aims to:

i) Perform the first simulations and experiments of elastic and elasto-inertial turbulence (EIT) in matching wall-bounded geometries.
ii) Apply methods for direct experimental measurement of time-resolved stress fields and compare with simulations.
iii) Improve microscopic models and predictions of elastic instability and turbulence.