MOTION OF A SINGLE SOLID AND FLUID SPHERE IN VISCOPLASTIC FLUIDS AND VISCOPLASTIC FLUID FLOW THROUGH FIXED BEDS: A UNIFIED SOLUTION

摘要

An approach to the calculation of drag and fall or rise velocity of a solid and Newtonian fluid spheres in viscoplastic fluids and to the calculation of pressure drop in viscoplastic fluid flow through random fixed beds of particles is suggested. It is based on the application of the modified Rabinowitsch-Mooney equations together with corresponding relations for consistency variables and on the application of the relationship of Hadamard-Rybczynski valid for both the fluid and solid spheres. The solution is concretized for Bingham, Casson and Robertson-Stiff flow models, and in the case of fixed beds also for Herschel-Bulkley flow model.