DYNAMICS OF FINITE-SIZED LIGHT SPHERES IN TURBULENCE etc15 Tracking Number 169Presentation: Session: Lagrangian aspects of turbulence 1 Room: Room F Session start: 10:30 Wed 26 Aug 2015 Varghese Mathai v.mathai@utwente.nl Affifliation: Physics of Fluids group, Faculty of Science and Technology, University of Twente Vivek Prakash vprakash@stanford.edu Affifliation: Prakash Lab, Department of Bioengineering, Stanford University Jon Brons j.abrons@student.utwente.nl Affifliation: Physics of Fluids group, Faculty of Science and Technology, University of Twente Chao Sun c.sun@utwente.nl Affifliation: Physics of Fluids group, Faculty of Science and Technology, University of Twente Detlef Lohse d.lohse@utwente.nl Affifliation: Physics of Fluids group, Faculty of Science and Technology, University of Twente Topics: - Lagrangian aspects of turbulence Abstract: We report experimental results on the Lagrangian dynamics of finite-size light particles in turbulence. Using an orthogonal camera setup and 3D particle tracking, we study the velocity and acceleration statistics of rigid light spheres in a water tunnel with nearly homogeneous and isotropic turbulence. The Reynolds number (Re) is varied from 180 to 300, and the study covers a range of size ratios (4 < D/η < 16) for marginally light spheres. We find that the normalised acceleration PDF decreases in intermittency with increasing size ratio - in qualitative agreement with the predictions of the Faxén corrected model. We also present preliminary results on the rotational dynamics of large light spheres in turbulence. |