Lagrangian Measurement of Particle Motion in Turbulent Field

Abstract

The paper presents techniques and apparatus for measuring the Lagrangian motion of particles (solid particles, droplets, or bubbles) suspended in a turbulent flow field. The Lagrangian measurement was made by an optical tracking method for illuminated particles, using solid-state image sensors. The experiment was conducted in nearly isotropic turbulent water flow field behind a grid to measure the Lagrangian motion of individual fluid particles (small polystyrene balls without the effect of buoyancy) by two procedures. The measured data and the analysis are found to give useful information on the turbulent particle diffusion and mixing processes.