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Subject Area

Mechanical Power Engineering

Article Type

Original Study

Abstract

A full water hammer model is developed and coded in the Mathcad software environment. The developed model constitutes a general platform for studying the water hammer transient incorporating the most legitimate parameters that affect the phenomenon. In this study, the fluid-structure interactions during water hammer transients were investigated through the affecting parameters such as pipeline material hysteresis behavior what is so-called viscoelasticity (VE) behavior, and unsteady friction (UF) with different coupling mechanisms such as friction coupling, Poisson coupling, and junction coupling which may be due to a free-to-move valve for system with a reservoir-pipe-valve. Based on the numerical results corresponding to the variation of parameters such as fluid flow rate, pipe length, pipe size, pipe material, pipe Poisson ratio and the effect of different coupling mechanisms for aforementioned system. The present results highlight the following: For shorter pipes, the frequency of the fluid wave is increased, and the wave amplitude attenuates faster than for longer pipes. The fluid wave characteristics depend on the pipe material. The maximum head with PVC material is higher than that with HDPE material, which has more hysteresis dissipation, as HDPE material has more viscoelastic behavior than PVC material, and so HDPE material has more damping effects than PVC material. Also, HDPE has a lower wave celerity than the PVC material, which leads to low frequency. For a higher Poisson ratio, the coupling between the fluid transient and pipe transient is strongly entrained; consequently, the wave amplitudes are amplified.

Keywords

water hammer; fluid-structure interaction; viscoelasticity; unsteady friction

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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