The classification of dilatant flow types

The kinematic vorticity number W has been used to classify the geometry of two-dimensional, non-dilatant flow as a function of flow vorticity. A similar kinematic dilatancy number A can be defined, which expresses flow geometry as a function of dilatancy rate. General two-dimensional flow geometry can be described in a simple, non-ambiguous way by just W and A. Mohr circles for flow can be used to illustrate this classification method.