Physical Understanding of Sudden Pressurization of Pipe Systems with Entrapped Air: Energy Auditing Approach

A global energy-auditing approach is used to describe the complex transient flow associated with sudden pressurization of a confined pipe system containing entrapped air pockets. The key concept is that the greatest pressures following pressurization are directly related to the amount of energy absorbed by the air pockets. The energy approach leads to an insightful understanding of the transient pressurization event, one that clarifies the underlying physics and that better explains several previously published observations. Moreover, the energy formulation leads to analytical algebraic expressions that can be numerically confirmed.