Drag correlations for particles of regular shape

Explicit equations are developed to characterize the effects of sphericity and Reynolds number of a particle on its drag coefficient. Experimental data are obtained from a wide range of sources, embracing various shapes including spheres, cube octahedrons, octahedrons, cubes, tetrahedrons, discs, cylinders, rectangular parallelepipeds and others. All these data are grouped within certain ranges of physical and kinematic conditions; sphericity range of 0.006-1 and Reynolds number range of 10−2 to 105. From the tabulations, equations for drag coefficient are developed and proposed based on the Kaskas equation. The constants in the equations are determined by the least-squares method and the calculated overall accuracy is approximately 97%. Manipulation of the constants allows three respective general equations to be proposed. Using these equations, prediction of drag coefficient of a particle based on its sphericity and Reynolds number would be simpler, easier and faster.