Simulation model for sub-millimeter part feeding on the asymmetrical saw-tooth surface with air drag

We have previously numerically and experimentally showed that micro-parts can be transported in one direction on a symmetrically vibrated asymmetrical sawtooth surface. However, the simulation model overestimated the feeding velocity of the micro-parts, particularly for those that are sub-millimeter-sized. In this work, we include air drag and study its effect on feeding velocity of sub-millimeter-sized micro-parts. The amplitude of the symmetrical vibration applied to the surface as a function of exciting frequency for the model is empirically formulated from the experiment data. The model is applied to simulate the response of the micro-parts against the exciting frequency for several ratios of the micro-parts´ length to the pitch of the saw-tooth. The attained results show that the model with air drag predicts well the behavior and magnitude of the feeding velocity in comparison with experiment data, while the model without air drag overestimates the velocity. We conclude that air drag plays important role in motion of micro-parts.