Turbulent flow of dense suspensions over viscous hyper-elastic walls*

The turbulent flow of suspensions of finite-size rigid spherical particles in channels with deformable walls is investigated. We perform direct numerical simulations with different wall elasticities at a fixed bulk Reynolds number of 5600 and compare the results against the particulate cases with a solid volume fraction of 10%. The flow is governed by the incompressible Navier– Stokes equations whereas the walls are modelled as a neo-Hookean material, satisfying the incompressible Mooney–Rivlin equation. A direct-forcing immersed boundary method is used to account for the particle-fluid interactions, combined with a collision model and lubrication corrections for short-range particle-particle and particle-wall interactions.

Our results indicate a non-monotonic behavior of the skin friction and turbulence activity when increasing the material elastic modulus. Comparing with the single-phase flow for the same wall elasticity, drag reduction is observed in the particulate cases for the highly elastic walls in contrast to the less deformable walls where particles induce drag increase. Detailed statistics of the fluid and particle phase will be presented at the conference.