List of Publications by Department for the Academic Year Damping in Transient Pressurized Flows
Abstract
Piping systems are commonly designed to withstand the first transient pressure peak, which is unaffected by dissipation. However,
for multiple operations of control equipment, for example, pump start-up following pump shutdown, and load acceptance following load
rejection on hydraulic turbines, an accurate prediction of the dissipation of pressure oscillations is needed to select a suitable time for the
second operation. For this purpose, following a simple procedure used for computing the dissipation of vibrations of bridges and other
structures with time, a method is presented to compute the dissipation of pressure oscillations in piping systems. Similar to structural engineering,
this method is simple to apply, does not require simulation of the entire system, is not computationally intensive, and gives
reasonable results for practical applications for a complex phenomenon whose mechanics is not well understood at present. An empirical
equation for the damping ratio is developed using dimensional analysis and by nonlinear regression. Comparisons of the computed and
experimental results for 17 tests conducted in laboratories all over the globe show good agreement. It is found that the damping ratio increases
with increases in the Reynolds number or Mach number and decreases with the diameter-to-length ratio of the pipeline. Uncertainty, quantified
using a Bayesian inference approach, shows that the model predicts the value of the damping ratio successfully
Author(s)
Sahad Khilqa
Coauthor(s)
Mohamed Elkholy
Journal/Conference Information
Journal of Hydraulic
Engineering,DOI: 10.1061/(ASCE)
HY.1943-7900.0001624, ISSN: 0733-9429, Volume: 145, Issue: 10, Pages Range: 1-10,