Relationship between the cluster theory of liquids and the Frenkel—Andrade viscosity model

Based on the reference data on the dynamic viscosity of the melts of halides of the elements of Groups 1 and 11, the approximating dependences in the form of cluster-associate and Frenkel’s models were constructed at various temperatures. In the framework of the cluster-associate viscosity model, which is being developed by the authors, entities in the form of virtual clusters and associates determine the melt viscosity and serve as the flow units to that the energy of fluid motion is applied. The Frenkel’s model allows us to estimate the activation energy of fluidity. Calculations show that there is a linear correlation between this energy and the cluster association degree obtained in the framework of the cluster-associate model, and the proportionality coefficient has the meaning of the activation energy per a cluster. This energy does not exceed the van der Waals energy of an unsaturated intermolecular bond characterizing the interaction of particles in a liquid.