DETAILED STRUCTURE OF PIPE FLOW WITH WATER HAMMER OSCILLATIONS

Abstract

Herein, the evolution and detailed structure of velocity and pressure fields of an oscillating axi-symmetric pipe flow arising from a rapid closure of a valve has been detennined through the solution, by the finite volume technique, of the full Navier Stokes equations. The method correctly predicts the distortion of the pressure waveform. The two-dimensional solution obtained confirms the one-dimensional solution obtained by the method of characteristics of the two-equation model incorporating frequency dependent friction typically used in modelling of transient pipe flows. The velocity field following valve closure is seen to consist of th e initial velocity profile upon which is superimposed an oscillating velocity component. The oscillating component is uni form in a pipe cross-section, at any instant. However, the profiles of initial steady state flow component and the uniform oscillating flow component are progressively distorted as the cumulative distance traversed by the wave increases