Wave speed calculation for water hammer analysis

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 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...

Effect of drop in pipe wall stiffness on water-hammer speed and attenuation

The effect of local drop of wall stiffness in pressurized waterways on the pressure wave speed and the wave attenuation during transients is investigated experimentally. A new signal-processing procedure to identify the presence of a weak reach is introduced and validated by physical experimentation based on assessing the pressure and vibration records acquired at both ends of a multi-reach ste...

A novel motor speed calculation method using square wave speed sensor signals via fast Fourier transform

This paper presents a novel motor speed measurement method and experimental results using the fast Fourier transform (FFT). Motor speed is obtained using the square wave output signal of a speed sensor. In the proposed method, the speed can be measured in a wide range, and transient speed changes can also be clearly observed. The experiments were conducted during start-up and in steady state. T...

Water hammer dissipation in pneumatic slug tests