Time-Dependent Pipe Forces Caused by Blowdown and Flow Stoppage

Abstract

Formulations are developed in this study for rapid estimates of time-and-space-dependent pipe reaction forces caused by either sudden blowdown or flow stoppage in a fluid piping system. The analytical model is a uniform pipe with arbitrary bends and friction, a pressure source at one end, and a sudden opening or closing value at the other end. A homogeneous mixture of liquid and ideal gas flows in the system. The method of characteristics is used to obtain fluid-mechanical properties, which then are employed to predict associated pipe loads. A graphical summary of results includes initial and steady blowdown forces, wave propagation forces, and local force-time behavior. The formulations presented are expected to provide a basis for confident, efficient, and economical design of pipe system layout and motion restraints.