Sedimentation of large particles in turbulent environments etc15 Tracking Number 182Presentation: Session: Multiphase and non-Newtonian flows 3 Room: Room D Session start: 15:00 Thu 27 Aug 2015 Walter Fornari fornari@mech.kth.se Affifliation: Linné Flow Centre and Swedish e-Science Research Centre (SeRC), KTH Mechanics, SE-100 44 Stockholm, Sweden Francesco Picano francesco.picano@unipd.it Affifliation: Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padua, Italy Luca Brandt luca@mech.kth.se Affifliation: Linné Flow Centre and Swedish e-Science Research Centre (SeRC), KTH Mechanics, SE-100 44 Stockholm, Sweden Topics: - Turbulence in multiphase and non-Newtonian flows Abstract: 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 0.5%-1.0%, while the solid to fluid density ratio 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 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. |