Equivalent Celerity in Water Hammer for Serially Connected Pipelines

Abstract

This paper presents the results of studies of water hammer phenomena in a physical model in combinations of two and three pipelines connected in series. The combined pipelines were made of steel and polypropylene. Pipelines made of one material type were connected in series in different configurations of diameter ratios and lengths of connecting sections. The obtained results were used to verify the value of the equivalent celerity calculated from equations derived using linear analysis of natural vibrations of the system. For verification of the equations, an algorithm in MATLAB was developed that allows one to easily calculate the equivalent celerity, ce, for N pipelines connected in series with varying diameter, length, and material composition. The ability to easily determine the value of the equivalent celerity allows the calculation of the maximum increase of pressure for a given configuration of pipelines, for example, after pipeline modernization or during making decisions on the installation of often expensive equipment to counter the negative effects of water hammer.