Effect of size distribution on the relation between coordination number and void fraction of spheres in a randomly packed bed

Counting the number of contact points on a particle in a packed bed is a ti me-consuming processes. So, usually, the number of contact points on a part icle surface in a randomly packed bed, i.e, tho coordination number, is est imated from the void fraction. Many researchers have proposed equations to estimate the coordination number From the void fraction in a packed bed, bu t all of these equations are obtained for a uniform sized sphere bed, Most actual powder has a wide size distribution, and the effect of the size dist ribution on the relation between the coordination number and the void fract ion is very important. We investigated the effect of the size distribution on the relation using our model and a computer simulation, Based on our res ults, the coordination number is not changed with the size distribution of the particle bed: however, the void fraction becomes smaller for wider part icle size distributions. It means that the value of the coordination number , as estimated by conventional equation for equal spheres from void fractio n data, is overestimated for a randomly packed bed of multi-component spher es with wider particle size distributions.