Suppression of Wall Turbulence in Dense Flowing Aerosols

Abstract

IT is well known that a marked reduction of the level of turbulence in Newtonian liquids can be had by adding a few parts per million of long-chain polymer¹. The same general effect can be obtained by using much larger quantities of small solid particles, although in this case the reduction of turbulence is far smaller and the physical mechanism rather different. Although reduction of turbulence by particles in gases is less widely known, it is more pronounced than in liquids, chiefly because of the greater difference in the material densities of the particles and fluid. Considerable indirect experimental evidence for the phenomenon in gases is accumulating. These observations include the reduction of convective heat transfer^2,3 and frictional pressure loss (paper by Rosetti and Pfeffer at the A.I.Ch.E. meeting, Puerto Rico, 1970, and ref. 4) of gases flowing turbulently in pipes.