Drag modulation by finite-size particles in viscoelastic Taylor-Couette turbulence
Phys. Rev. Fluids 11, 104306 – Published 22 October, 2026
DOI: https://doi.org/10.1103/6hkq-btnz
Abstract
We experimentally investigate drag modulation by finite-size particles in viscoelastic Taylor-Couette turbulence. Three spheroidal particle shapes, namely oblate, spherical, and prolate particles, are considered. By combining global torque measurements with particle-distribution measurements, we identify two distinct particle-polymer-turbulence coupling regimes. At lower Reynolds number, the flow is particle dominated: polymer elasticity only weakly modifies the carrier turbulence, while finite-size particles introduce additional particle-related stresses and locally enhance the particle-polymer interaction. In this regime, the particle-induced drag penalty increases monotonically with polymer concentration. At higher Reynolds number, the flow becomes polymer dominated: stronger elasticity suppresses turbulent fluctuations and weakens the ability of particles to enhance angular momentum transport, leading to a nonmonotonic dependence of the particle-induced drag penalty on polymer concentration. Particle shape further modulates this particle-polymer-turbulence coupling. Spherical particles generate larger torque than oblate and prolate particles, and this shape dependence is amplified in the viscoelastic fluid, suggesting that polymer elasticity enhances the sensitivity of the global drag to shape-dependent local disturbances. Particle-distribution measurements provide the spatial signature of the two regimes: polymers have little influence at low Reynolds number, whereas at high Reynolds number they reduce the near-wall accumulation of spherical particles and make the axial distribution more strongly organized by Taylor vortices. These results reveal the regime-dependent coupling mechanisms in complex multiphase turbulence, where dispersed particles, polymer elasticity, turbulence, and secondary flows act as a coupled dynamical system to determine the particles and momentum transport.
