Flow Pattern and Frictional Losses in Pulsating Pipe Flow : Part l, Effect of Pulsating Frequency on the Turbulent Flow Pattern

Pulsating turbulent pipe flow was measured at the time - averaged Reynolds number of about 5.7×1-4 and over wide ranges of both frequency and velocity amplitude ratio. The flow pattern in an incompressible turbulent pipe flow was found to be described by four characteristic parameters and not to be affected so much by four characteristic parameters and not to be affected so much by velocity amplitude ratio. Further, the flow patterns were classified into three types, i.e., quasi-steady, intermediate, and inertia dominant ones with respect to the dimensionless frequency ω'. The values of ω' representing the limits between three regions were proposed.