# Engineering Mechanics

Proceedings Vol. 32 (2026)

ENGINEERING MECHANICS 2026

Copyright © 2026 Institute of Thermomechanics of the Czech Academy of Sciences, Prague

 

Burda R., Vondál J., Sedlář M., Abrahámek P.
pages 21 - 24, full text

Water hammer poses a significant risk to the integrity of piping systems and pumps, particularly in critical applications such as nuclear power plants. This transient phenomenon is characterized by rapid changes in pressure and flow, often resulting from pump shutdowns or valve closures. This paper presents a detailed computational analysis of water hammer using the 1D CFD software Flownex. The study investigates the impact of various system parameters on the pressure response, specifically focusing on the influence of pump characteristics, the number of hydraulic accumulators, the gas-to-liquid ratio within those accumulators, and the presence of non-condensable air in the water. Results indicate that additional accumulators and optimized gas ratios mitigate pressure peaks. Also, the presence of non-condensable gas plays a crucial role in damping pressure fluctuations through the alteration of the fluid's bulk modulus.

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