Abstract
A model for the incipient motion of a particle resting on a bed of like particles carried by a submerged oscillating plate is presented. The model is developed by extending the theory of Stevenson et al. (Chem. Eng. Sci. 57, (2002) 4505) who gave a force balance for limiting equilibrium of a particle within the viscous sublayer at a pipe wall to the present case by including a d'Alembert type force due to the oscillatory motion of the plate. Simultaneous equations are presented that can estimate the phase and frequency of first motion as a function of system parameters. The new model is compared with the data of Bagnold (Proceedings of the Royal Society, London A 187, (1946) 1–15) and is shown to be in excellent agreement.