A broad ranging study of the fluid flow in packed beds of uniform diameter spheres has been implemented by the method of numerical simulation. The parametric extent of the present study encompassed both laminar and turbulent flows, random and regular packings of the spheres, bed containments in both rectangular ducts and circular pipes, and beds of either bounded or unbounded lateral extent. The regular packings included bodycentered cubic, face-centered cubic, and simple cubic. Comparisons were made between the simulation-based results and relevant experimental data using variables that emerged from the experimental correlations. In particular, the Reynolds number range of the Ergun flow regime for packed beds of unbounded extent was identified. In addition, for random packed beds of bounded extent, very good agreement between the predicted and experimentally determined friction factors was found to exist. The level of agreement was sufficiently good to validate the simulation model and its implementation. The pressure drop-fluid flow results are presented in terms of friction factor-Reynolds number relationships. These dimensionless quantities were defined in terms of physical variables commonly used throughout the packed-bed literature.