An investigation of particle dynamics within a centrifugal accelerator type erosion tester

Particle impact erosion is usually tested experimentally using one of two m ajor types of erosion testing device; the gas-blast tester and the centrifu gal accelerator type tester. The influence of the choice of the tester on t he erosion results obtained has been recognised, together with the need for a better understanding of particle dynamics within the testers to allow co rrect interpretation of the erosion test results. To date, relatively little work has been carried out on understanding parti cle dynamics in the centrifugal tester, and this paper attempts to redress this. The paper considers the dynamics of particles travelling down the acc eleration tube in the tester. A comprehensive physical model is described t aking account of airflow in the acceleration tubes, particle rotation and f riction effects. This led to the development of a computational model to pr edict the particle velocity vector (particle velocity and exit angle). The predictive model indicates the important influence of particle shape on par ticle dynamics and suggests that particle size has little effect. This impl ies a sensitivity of particle velocity and exit angle to the coefficient of friction of the particle in the acceleration tubes. Experimental measureme nts were carried out and the results verified the predictions of the model. (C) 2001 Elsevier Science B.V. All rights reserved.