Particle imaging velocimetry experiments and lattice-Boltzmann simulations on a single sphere settling under gravity

Ten Cate, A.; Nieuwstad, C.H.; Derksen, J.J.; Van den Akker, H.E.A.

doi:doi:10.1063/1.1512918

Particle imaging velocimetry experiments and lattice-Boltzmann simulations on a single sphere settling under gravity

Title

Particle imaging velocimetry experiments and lattice-Boltzmann simulations on a single sphere settling under gravity

Author

Ten Cate, A.
Nieuwstad, C.H.
Derksen, J.J.
Van den Akker, H.E.A.

Faculty

Applied Sciences

Department

Multi-Scale Physics

Date

2002-10-03

Abstract

A comparison is made between experiments and simulations on a single sphere settling in silicon oil in a box. Cross-correlation particle imaging velocimetry measurements were carried out at particle Reynolds numbers ranging from 1.5 to 31.9. The particle Stokes number varied from 0.2 to 4 and at bottom impact no rebound was observed. Detailed data of the flow field induced by the settling sphere were obtained, along with time series of the sphere’s trajectory and velocity during acceleration, steady fall and deceleration at bottom approach. Lattice–Boltzmann simulations prove to capture the full transient behavior of both the sphere motion and the fluid motion. The experimental data were used to assess the effect of spatial resolution in the simulations over a range of 2–8 grid nodes per sphere radius. The quality of the flow field predictions depends on the Reynolds number. When the sphere is very close to the bottom of the container, lubrication theory has been applied to compensate for the lack of spatial resolution in the simulations.

Subject

gravity
sedimentation
velocity measurement
lattice theory
Boltzmann equation
two-phase flow
digital simulation
lubrication
rheology
flow simulation