Effect of Initial Acceleration History on Transition to Turbulence in Pipe Flow

Abstract

Turbulent flows in pipes are usually accelerated from rest using blowers and pumps in practical applications. The history of cross-sectional mean velocity consists of the initial stage of flow acceleration and the subsequent stage of constant cross-sectional mean velocity. The effect of the initial acceleration on the transition to turbulence in such flows is not fully understood yet. In the present study experimental investigation is carried out to reveal this effect in a circular pipe using air as the working fluid.