Transient Pressure Analysis in Piping Networks due to Valve Closing and Outlet Pressure Pulsation

Abstract

This paper investigates the transient flow and pressure developments in a piping network due to design parametric and operational variations. Numerical simulations using both the method of characteristics and the finite difference formulation are performed and compared. The transient fluid pressure pulsations in the pipes are examined in both the time and frequency domains using a Fast Fourier Transform (FFT) algorithm. The parametric studies consider changes in i) the main pipe size, ii) the valve closing time at the branch outlet, iii) the piping system configuration (both single and multiple branched systems), and iv) the frequency of pressure pulsation at the branch outlet (manifold effect). The paper discusses the sensitivity of the transient fluid pressure and the excitability of the piping natural frequencies at various locations of the pipes, due to valve closing and manifold effects at the branch outlet. The effects of resonance due to pressurefrequency variation at the branch outlet are also studied and general conclusions are drawn from these results.