Transport and handling of complex fluids consumes large amounts of energy worldwide, and improving their mixing and heat transfer crucial from process industry to medicine.
A tiny amount of polymers can completely change fluid flow, reducing friction at large scales, but creating a whole new kind of turbulence at small scales. Such elastic turbulence has received exponentially increasing attention, as it increases mixing and heat transfer in microfluidics (e.g. lab-on-a-chip), aids cleaning of fluids in the ground, but also result in undesired chaotic flow (cell sorting, blood flow).
However, large gaps exist in understanding elastic and elasto-inertial turbulence, and multiscale interactions needed to sustain it. We propose ambitious direct numerical simulations (DNS) of complex fluids connected to the ERC project StG-2019-MUCUS (852529).
The project will simulate elasto-inertial turbulence in duct flows to examine its interaction with fluid rheology and turbulence triggered by multiphase inclusions by a 3D finite-difference method for elastoviscoplastic (EVP) fluids with excellent scaling properties that recently enabled the first single- and multiphase DNS of turbulent EVP flows.
The incompressible Navier-Stokes equations are solved using an efficient FFT-based pressure projection method allowing massively parallel simulations of turbulent flows, fully coupled with the evolution equations of EVP stresses and multiphase inclusions.
Outi Tammisola, KTH Royal Institute of Technology - Sweden