EXPERIMENTAL INVESTIGATION ON INITIAL DISTURBANCES IN PULSATING PIPE FLOWS

J J Miau,J Y Dai

doi:10.1142/s2010194514603810

Abstract

Growth of the initial disturbances in pulsating pipe flows was examined in this study from the point of view of Rayleigh instability. Experimental results obtained show that the instability is initiated in the developing region during the deceleration phase when an inflection point is obviously present in the velocity profile. Moreover, the results obtained are able to unveil the process regarding the disturbances get amplified and re-laminarized with respect to the phase angle and the radial location.

Highlights

Studying pulsating pipe flows can be traced to the earlier work of Womersley[1] and Uchida[2], who obtained the asymptotic solutions of pulsating pipe flows based on the assumption that a pipe flow is fully developed with given pressure gradient
Experimental Investigation on Initial Disturbances in Pulsating Pipe Flows point can be resulted in the velocity profile at such a moment
Signal analysis was carried out with a technique based on Hilbert-Huang Transformation (HHT).[18]

Summary

Introduction

Studying pulsating pipe flows can be traced to the earlier work of Womersley[1] and Uchida[2], who obtained the asymptotic solutions of pulsating pipe flows based on the assumption that a pipe flow is fully developed with given pressure gradient. Experimental Investigation on Initial Disturbances in Pulsating Pipe Flows point can be resulted in the velocity profile at such a moment. A boundary-layer type hot-wire probe was employed to obtain the instantaneous velocity information of the pulsating pipe flow.

Results

Conclusion