PARTICLE VELOCITY AFTER COLLISION

Abstract

An experimental method has been developed to determine the values of the two components of the particle velocity after collision as a function of impact angle and velocity. The experimental work was performed on four types of spherical particles (aluminium oxide, glass, polystyrene and fertilizer) impacted on steel plate of 1 mm thickness, in the impact angle range of 11o < αe < 90o. Linear relation was found between the difference in normal components of the particle velocity before and after collision and the sine of the impact angle. The extension of this relation to the small impact angle range provided the same results as those found by Muschelknautz, the value of the normal component of the particle velocity after collision is higher than that before collision, which means that at small impact angles the normal coefficient of collision is higher than 1, thereby the continuous movement of the particles in a horizontal pneumatic conveying system can be explained. It was found that at large impact angles the change in the normal component of the particle velocity before and after collision is greater in the case of large particles. Generally the change in the parallel components of the particle velocity before and after collision is greater in the case of small particles. Due to the simplicity of the experimental work, this method can be easily used in the prediction of particle velocity after collision.