New Numerical Model and Technique for Waterhammer

Abstract

HOW efficiently a second‐order model is handled is analysed for simplified equations governing waterhammer appearance in piping systems. A series solution method and a Newton‐Raphson method with new calculation steps are proposed, which are efficient numerical methods, through omitting trivial terms computed within a truncation error. With fewer calculations than required previously, the proposed methods can give a solution with a required accuracy without any iteration. The second‐order model, therefore, offers more accurate and efficient methods than those offered by a first‐order model. However, the second‐order model causes an error in computing steady flows; ways to remove or reduce this error are shown. The validity of the analyses is examined by numerical computations in which system parameters are varied over a wide range of parameters.