Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.
Concept
Water hammer
Summary
Hydraulic shock (colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion, usually a liquid but sometimes also a gas is forced to stop or change direction suddenly; a momentum change. This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe.
This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse. It is possible to reduce the effects of the water hammer pulses with accumulators, expansion tanks, surge tanks, blowoff valves, and other features. The effects can be avoided by ensuring that no valves will close too quickly with significant flow, but there are many situations that can cause the effect.
Rough calculations can be made using the Zhukovsky (Joukowsky) equation, or more accurate ones using the method of characteristics.
In the 1st century B.C., Marcus Vitruvius Pollio described the effect of water hammer in lead pipes and stone tubes of the Roman public water supply.
Water hammer was exploited before there was even a word for it.
The Alhambra, built by Nasrid Sultan Ibn al-Ahmar of Granada beginning AD1238, used a hydram to raise water. Through a first reservoir, filled by a channel from the Darro River, water emptied via a large vertical channel into a second reservoir beneath, creating a whirlpool that in turn propelled water through a much smaller pipe up six metres whilst most water drained into a second, slightly larger pipe.
In 1772, Englishman John Whitehurst built a hydraulic ram for a home in Cheshire, England. In 1796, French inventor Joseph Michel Montgolfier (1740–1810) built a hydraulic ram for his paper mill in Voiron. In French and Italian, the terms for "water hammer" come from the hydraulic ram: coup de bélier (French) and colpo d'ariete (Italian) both mean "blow of the ram". As the 19th century witnessed the installation of municipal water supplies, water hammer became a concern to civil engineers.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.