2000/11/08 by A. La Porta, Greg A. Voth, Alice M. Crawford +2 · 8 citations
Engineering · Physics and Astronomy · #Acceleration #Advection #Fluid Dynamics and Turbulent Flows #Fluid dynamics #Granular flow and fluidized beds #Mixing (physics) #Particle (ecology) #Particle Dynamics in Fluid Flows #Reynolds number #Scaling #Turbulence #physics.flu-dyn
paper · pdf · doi:10.1038/35059027
7 pages, 4 figures
arxiv created 2000/11/08 · openalex publication_date 2001/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The motion of fluid particles as they are pushed along erratic trajectories by fluctuating pressure gradients is fundamental to transport and mixing in turbulence. It is essential in cloud formation and atmospheric transport, processes in stirred chemical reactors and combustion systems, and in the industrial production of nanoparticles. The perspective of particle trajectories has been used successfully to describe mixing and transport in turbulence, but issues of fundamental importance remain unresolved. One such issue is the Heisenberg-Yaglom prediction of fluid particle accelerations, based on the 1941 scaling theory of Kolmogorov (K41). Here we report acceleration measurements using a detector adapted from high-energy physics to track particles in a laboratory water flow at Reynolds numbers up to 63,000. We find that universal K41 scaling of the acceleration variance is attained at high Reynolds numbers. Our data show strong intermittency---particles are observed with accelerations of up to 1,500 times the acceleration of gravity (40 times the root mean square value). Finally, we find that accelerations manifest the anisotropy of the large scale flow at all Reynolds numbers studied.