Classification of turbulence modification by dispersed spheres using a novel dimensionless number.

A novel dimensionless parameter, the particle moment number Pa, was derived using dimensional analysis of the particle-laden Navier-Stokes equations, in order to understand the underlying physics of turbulence modification by particles. A set of 80 previous experimental measurements where the turbulent kinetic energy was modified by particles was examined, and all results could clearly be divided into three groups in Re-Pa mappings. The turbulence attenuation region was observed between the augmentation regions with two critical particle momentum numbers.