Novel Explicit Formulae for Estimation of Free-Fall Conditions for Solid Particles

Abstract

A series of correlations have been proposed which make it possible to predict, accurately and rapidly, the drag coefficient, terminal velocity and diameters of spherical solid particles falling freely through quiescent Newtonian fluids for a wide range of Reynolds numbers of particles (Re_t = 10⁻¹ - 10⁵). The experiments were conducted with dimethyl phthalate and 0,463 − 4,911 mm glass beads in a glass column (ID 10 cm). The employment of the proposed formulae avoids the need for trial-and-error computations. The formulae favorably compare with own and literature experimental data as well as with much more involved regression equations for the drag coefficient jn literature.