Prediction of particle rotation in a centrifugal accelerator erosion tester and the effect on erosion rate

A new computational model for the prediction of particle rotational velocity in a centrifugal accelerator erosion tester is presented. Particles emerging from the acceleration tube of the tester have a rotation and this is known to affect erosion. The model proposes that the particle rotational speed is related to the particle shape angle and size of the particle, the length of the acceleration tube, the disc rotational velocity and the friction coefficient between the particle and the wall of acceleration tube. The mass of the particle does not affect the rotational velocity of the particle. It is shown that there is a critical shape angle of the particle necessary for particle rotation to occur. This is equal to the static friction angle between the particle and the wall of the acceleration tube. The particle will rotate if the shape angle is less than the critical angle, otherwise, sliding of the particle will occur. The predictive results of the model agreed well with the experimental measurement of particle rotation. An accurate simulation model is a useful tool in estimating particle rotational velocities as experimental measurements are relatively difficult to carry out. A consideration of rotational velocity indicates a 5% increase in dynamic energy. This may have some effect on erosion rate.