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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Water engineering : Numerical comparison of rapid-filling-pipe models with trapped air
Numerical comparison of rapid-filling-pipe models with trapped air
f air-water problems in a rapid filling pipeline are simulated by three models. A full water elastic model
considers the elasticity of the whole water region, which is solved by using the methods of characteristics (MOC) of
rectangular grid. The entrapped air is treated as ideal gas. The first approximation is to neglect the movement of the airwater
interface. The second simplification is the application of the rigid water theory for the whole water phase.
Comparisons of the calculated and measured pressures are conducted to verify the models. The range of validity
associated with two simplifications is also examined. The simplification of constant water length greatly reduces solution
complexity avoiding interpolation for moving air-water interface, and the calculation error decreases as the initial air
fraction diminishes. The second simplification makes the governing equations simple and the solutions efficient, and
avoids the complexity of MOC. The error gradually increases as the initial air pocket volume decreases; especially the
results would be undependable when the initial entrapped air pocket is relatively small.Form Required :
File Size : 466,431 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Water engineering
Date Published : 19/08/2015
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