Experimental Measurement of Single-Particle Dispersion in High Reynolds Number Turbulence*

We report Lagrangian measurements of single-particle dispersion in a high Reynolds number (up to a Taylor microscale Reynolds number of $R_{\lambda} = 815$) turbulence experiment. The motion of tracer particles is followed optically in three dimensions using multiple high speed cameras. Such direct measurement is not possible from Eulerian techniques. We compare our measurements with previous experimental data, stochastic models and DNS. This work is supported by the National Science Foundation and the Max Planck Society.