Diverging and Converging Flows of Dilute Polymer Solutions : 2nd Report, Universal Velocity Profile of Turbulent Diverging Flow

Abstract

Velocity profiles of a turbulent diverging flow are formulated by using a wake function. the frictional coefficient, the stress distributions and the mixing length are calculated by an empirical equation, which includes the result of Newtonian fluids. In a Newtonian flow, the frictional coefficient decreases when the fluid flows in downstream direction because of the inverse pressure gradient. Then, the position of the maximum stress shifts to the center from the wall, and the polymer additives promote this tendency. when the pressure gradient is small, the mixing length of a diverging flow is decreased by the addition of polymers, but it is increased when the pressure gradient is large.