Author(s): R.E. Slot
Abstract: This note presents a general formula for the terminal velocity of a sphere in a viscous fluid (no wall effects). The formula holds for Reynolds numbers up to 2000 and it has an accuracy better than 2% (so far as can be checked against experimental data with errors of the same order of magnitude). Besides, a less accurate formula (5%) for the terminal velocity of irregular shaped objects is presented which holds for Reynolds numbers up to 8000. Furthermore, formulae for the sedimentation diameter and the nominal diameter are presented. Both formulae can be useful in fall of velocity analysis with settling tubes. The presented formulae have no physical background but they can replace tabulated data or diagrams.