On the Resistance Coefficient–Reynolds Number Relationship for Fluid Flow through a Bed of Granular Material

Abstract

The resistance coefficient–Reynolds number relationship for a bed of spherical particles, closely graded about a mean size, is considered and it is shown that this relationship correlates with that for a bed of non-spherical particles, provided a suitable allowance for particle shape is made.It is shown that for very large or very small values of the Reynolds number the co-ordinates of the resistance coefficient–Reynolds number curve fall closely about a mean line but for the transition-range the points suffer considerable scatter—probably due to the indeterminate nature of the flow in the pore channels for this range of the Reynolds number.Curves are given showing the frequency of occurrence of variations in the resistance coefficient, and an example of the practical application of these curves to a design problem is fully worked out.Curves relating the resistance coefficient to the Reynolds number for beds of particles of various degrees of angularity are put forward tentatively, these relationships being, as yet, not completely established.