Sensitivity of creep coefficients to the fundamental water hammer period in viscoelastic pipes

Abstract

ABSTRACT In this study, by calibrating creep coefficients using two methods of creep function and transient pressure, the effect of Kelvin-Voigt elements on creep behavior and pressure fluctuations is investigated. The pressure error of different Kelvin-Voigt models shows that the accuracy of three and four-element models for pipes longer than 1000 m in the first method is higher than the second method. For pipes less than 1000 meters, the accuracy of the three and four-element models is the same in both methods. In the two-element model for pipes longer than 720 m, the accuracy of the first method is higher than the second method and at lengths less than 720 m, the result is the opposite. The error analysis using the two approaches revealed that the one-element Kelvin-Voigt model is largely inaccurate (led to error up to 60%) and hence it is not appropriate for predicting transient pressures in viscoelastic pipes.