DRAG ON MULTIPLE SPHERE ASSEMBLIES SUSPENDED IN NON-NEWTONIAN TUBE FLOW

The drag forces experienced by single and multiple sphere assemblies s uspended in non-Newtonian tube-flow were investigated under different levels of fluid viscosity of aqueous CMC solutions (m=2.0 to 21.1 Pa-s (n) and n=0.73 to 0.82), flow rate (0.02 to 0.86 kg/s) and particle co ncentrations (1.53 to 11.01% on a volume basis). It was found that an increase in particle concentration resulted in an increase in drag for ce experienced by each sphere in an assembly. It was also observed tha t the presence of identical assemblies upstream and downstream of the single test assembly (multiple assembly case), resulted in drag force increases per sphere from 14% for low concentration to 25% for high co ncentration. An equation was developed to predict a drag correction fa ctor for Stokes' equation for the multiple assembly configuration base d on particle concentration.