Experimental measurement of the drag coefficient for a falling raw sugar particle

Abstract

The effects of drag forces on irregularly shape crystals have a significant impact on many industrial applications. The drag coefficient for a falling raw sugar crystal was experimentally determined by filming crystals falling through ethanol using high-speed photography. These images were analysed to calculate the velocity and acceleration of the particle, and via a force balance the drag coefficient of the crystals was calculated. The measured results were compared to the predictions of two common correlations for falling particles. It was found that these correlations over predicted the drag coefficient under the conditions observed. The drag coefficient for a falling sugar crystal was found to be more appropriately described by .