Clustering in laboratory and numerical turbulent swirling flows

Abstract

We study the three-dimensional clustering of velocity stagnation points, of nulls of the vorticity and of the Lagrangian acceleration, and of inertial particles in turbulent flows at fixed Reynolds numbers, but under different large-scale flow geometries. To this end, we combine direct numerical simulations of homogeneous and isotropic turbulence and of the Taylor-Green flow, with particle tracking velocimetry in a von Kármán experiment. While flows have different topologies (as nulls cluster differently), particles behave similarly in all cases, indicating that Taylor-scale neutrally buoyant particles cluster as inertial particles.

References in corpus (6)

• Turbulent transport of material particles: An experimental study of finite size effects
• A trilinear method for finding null points in a 3D vector space
• Acceleration of heavy and light particles in turbulence: comparison between experiments and direct numerical simulations
• Clustering of vector nulls in homogeneous isotropic turbulence
• Broken mirror symmetry of tracer's trajectories in turbulence
• Settling and clustering of particles of moderate mass density in turbulence