Creeping Flow of Viscoelastic Fluid Through a Packed Bed: Effect of Particle Shape and Porosity

Experiments were conducted to elucidate the effect of particle shape and porosity on frictional pressure drop for the flow of viscoelastic fluids through a packed bed under creeping flow regime. Extensive pressure drop-flow rate data were generated using different packing materials such as cylinders of different aspect ratios, square plates, triangles, and spheres covering a wide range of sphericity, 0.546 phi 1. Effect of bed porosity has been determined using uniform-size spheres of different diameters (4.38mm, 5.76mm, and 6.78mm), covering column to particle diameter ratio in the range of 13.96-21.62; while porosity varies in the range of 0.345-0.375. The experimental results indicate that the modified Ergun correlation, proposed by Sobti and Wanchoo (2014), can adequately be applied for the nonspherical particles, provided the equivalent volume mean diameter (D-eq) together with sphericity (phi) is used instead of the diameter of the spherical particle (D-p), i.e., D-p=D-eq phi. Further, an attempt has been made to suitably define a packing structure parameter, [(1-E)/(E phi)], which could well capture the balancing effect between porosity and sphericity.