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  • Parameters affecting water-hammer wave attenuation, shape and timing Part 1 : mathematical tools
    Bergant, Anton ...
    This two-part paper investigates key parameters that may affect the pressure waveform predicted by the classical theory of water-hammer. Shortcomings in the prediction of pressure wave attenuation, ... shape and timing originate from violation of assumptions made in the derivation of the classical waterhammer equations. Possible mechanisms that may significantly affect pressure waveforms include unsteady friction, cavitation (including column separation and trapped air pockets), a number of fluid-structure interaction (FSI) effects, viscoelastic behaviour of the pipe-wall material, leakages and blockages. Engineers should be able to identify and evaluate the influence of these mechanisms, because first these are usually not included instandard water-hammer software packages and second these are often "hidden" in practical systems. Part 1 of the two-part paper describes mathematical tools for modelling the aforementioned mechanisms. The method of characteristics transformation of the classical water-hammer equations is used herein as the basic solution tool. In separate additions: a convolution-based unsteady friction model is explicitly incorporated; discrete vapour and gas cavity models allow cavities to form at computational sections; coupled extended water-hammer and steel-hammer equations describe FSI; viscoelastic behaviour of the pipe-wall material is governed by a generalised Kelvin-Voigt model; and blockages and leakages are modelled as endor internal boundary conditions.
    Source: Journal of hydraulic research = Journal de recherches hydrauliques. - ISSN 0022-1686 (Letn. 46, Št. 3, 2008, str. 373-381)
    Type of material - article, component part
    Publish date - 2008
    Language - english
    COBISS.SI-ID - 10588187

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