Water Hammer in Steel–Plastic Pipes Connected in Series

Water hammer dissipation in pneumatic slug tests

Water Hammer with Column Separation:

Column separation refers to the breaking of liquid columns in fully filled pipelines. This may occur in a water hammer event when the pressure drops to the vapor pressure at specific locations such as closed ends, high points or knees (changes in pipe slope). A vapor cavity, driven by the inertia of the parting liquid columns, will start to grow. The cavity acts as a vacuum, a low-pressure poin...

Multiple Scales Analysis of Water Hammer Attenuation

A multiple scales analysis is used to construct a uniformly accurate approximation to water hammer pressure wave attenuation that is initiated by a sudden valve opening. The method of analysis is well suited to the study of a water hammer that possesses several time scales and is applied to a mild generalization of the classical equations. It should prove useful for finding attenuation curves w...

Water hammer simulation by explicit central finite difference methods in staggered grids

Four explicit finite difference schemes, including Lax-Friedrichs, Nessyahu-Tadmor, Lax-Wendroff and Lax-Wendroff with a nonlinear filter are applied to solve water hammer equations. The schemes solve the equations in a reservoir-pipe-valve with an instantaneous and gradual closure of the valve boundary. The computational results are compared with those of the method of characteristics (MOC), a...

Detonation and Transition to Detonation in Partially Water-Filled Pipes

Detonations and deflagration-to-detonation transition (DDT) are experimentally studied in horizontal pipes which are partially filled with water. The gas layer above the water is stoichiometric hydrogen–oxygen at 1 bar. The detonation wave produces oblique shock waves in the water, which focus at the bottom of the pipe due to the curvature of the walls. This results in peak pressures at the bot...