Sedimentation of large particles in turbulent environments

• The aim of the present study is to investigate the sedimentation of large non-colloidal spherical particles in both quiescent and turbulent environments. To this aim, Direct Numerical Simulations are performed using an Immersed Boundary Method to account for the dispersed phase. The solid volume fractions considered are in the range φ = 0.005−0.010, while the solid to fluid density ratio ρp/ρf is set equal to 1.02. The particle diameter is chosen to be approximately 12 Komlogorov lengthscales in nominal conditions. The results show that the mean settling velocities Vt decrease in the turbulent cases. The overall drag is increased both by the non-linear finite Reynolds number behavior and by unsteady effects, which are negligible in quiescent cases. 

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering (hsv//eng)

Keyword

Numerical methods

Reynolds number

Turbulence

Turbulent flow

Finite Reynolds number

Immersed boundary methods

Particle diameters

Settling velocity

Solid volume fraction

Spherical particle

Turbulent environments

Unsteady effects

Sols

Publication and Content Type

ref (subject category)

kon (subject category)