Particle alignment and volume fraction for ellipsoidal particles

![CDATA[This paper studies rheological properties of elongated ellipsoidal particles in a model annular shear cell in stress controlled flow condition using the discrete element method (DEM). Particle orientation and volume fraction of the flow are considered. Probability distribution of particle orientation angle exhibits the effect of different shear rates as such that at lower shear rates there is a systematic increase in number particles aligned to the direction of flow with the increase of load, which is not found in the study of higher shear rates. Then, a correlation between orientation angle and volume fraction for different shear rates is observed. It shows that, for the particle assembly volume fraction above 0.55, there is a noticeable influence of shear rate on the relationship between orientation angle and volume fraction. For volume fraction below 0.55, the relationship curve collapse into a single curve indicating that the relationship is no longer affected by variation of shear rate. This observation has a similar pattern with the correlation between kinetically scaled stress and volume fraction, which has been used to determine the transition between kinetic and intermediate regime for spherical particles.]]