Propagation of Disturbance in Fluid Lines

Abstract

The purpose of this paper is to investigate the phenomena of the decay and dispersion of a disturbance pulse as it travels in a fluid along a pipe. A disturbance has associated with it deviations in the mean velocity and pressure. The disturbance pulse, therefore, may be considered as a velocity or a pressure pulse. By decay we mean here a decrease in the intensity, and by dispersion an increase in the width of the pulse with time. In an ideal nonviscous fluid contained in a rigid pipe, decay and dispersion do not occur, but are observed in the viscous fluids. A reflection of the pulse from a closed free end of the pipe also causes decay and dispersion. It is observed that for sufficiently low values of the coefficient of friction the viscous effects may be approximated by a pure decay without dispersion.