Measurement and modeling of the settling velocity of isometric particles

The sedimentation of solid particles of simple form and complex form has been studied. The applied data in the case of isometric particles have been compared to those of spherical particles of same volume. This comparison allows highlighting an equivalent sedimentation diameter concept.Dimensionless factor depending on the extended equivalent diameter, the geometric aspect of the particle and the flow have been defined. The use of this factor allows finding an interrelationship with another dimensionless factor which is the Archimedes number. This last depends on the physical parameter of the particle and the carrying fluid. The numerical treatment of this interrelationship permitted to deduct an empirical model for the settling velocity of particles. This model is applied with success to the data of the considered measures and well compared to the results obtained by other models.

Graphical abstractThe sedimentation of particles of simple form and complex form is studied. A dimensionless factor depending on the particle shape and flow characteristics is defined. It varies with Archimedes number. The relationship between these two parameters leads to a model calculating the settling velocity. The results obtained agreed well with those of other models (figure).Figure optionsDownload full-size imageDownload as PowerPoint slideComparison with the results of other models.