The effect of a steady drift on the dispersion of a particle in turbulent fluid

The effect of a steady deterministic drift on the dispersion of particles suspended in a stationary homogeneous turbulent field is examined using previously reported closed equations of the mean-squared particle displacement. The existence of negative particle velocity correlations is demonstrated. The dependence of the particle diffusivity and kinetic energy on the inertia and drift factors is evaluated for a model turbulence spectrum. Asymptotic formulae are obtained for the case of dominant deterministic motion. The theory is applied to analysis of the experimental data of Snyder & Lumley (1971), and good and consistent agreement with these asymptotic formulae was obtained after accounting for the quasi-stationarity of particle velocity correlation functions in decaying turbulence.