Study of ellipsoid motion in Couette flow and the influence from particle and fluid inertia
Title: Study of ellipsoid motion in Couette flow and the influence from particle and fluid inertia
DNr: SNIC 2015/1-209
Project Type: SNIC Medium Compute
Principal Investigator: Fredrik Lundell <fredrik@mech.kth.se>
Affiliation: Kungliga Tekniska högskolan
Duration: 2015-08-28 – 2016-09-01
Classification: 20301 10399
Homepage: https://www.mech.kth.se/mech/info_staff.jsp?ID=66
Keywords:

Abstract

Understanding the motion of a single ellipsoidal particle suspended in a shear flow is fundamental for modeling any flow containing elongated particles, as seen for example in papermaking, aerosols and ice particles in clouds. The models are both used for predicting the rheology of such suspensions as well as the orientation of the individual particles. This work focuses on Lattice Boltzmann (LB) simulations of an ellipsoidal particle in a Couette flow, with the aim to study the transitions in both particle rotation and orbit shape. The transitions are believed to be controlled by two dimensionless parameters connected to fluid and particle inertia respectively. Fluid inertia is controlled by the Reynolds number, Rep=Gl2/ν, where G is the shear rate, l is the particle length and ν is the kinematic viscosity of the fluid while particle inertia is controlled by the Stokes number, St=αRep, where α is the density ratio between particle and fluid.