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You are here : eLibrary : IAHR World Congress Proceedings : 34th Congress - Brisbane (2011) : THEME 4: Responding to Shifting Water Resources : Sufficient conditions for the passivity of numerical unsteady friction operators for transient pipe ...
Sufficient conditions for the passivity of numerical unsteady friction operators for transient pipe flow
Author : Aaron C. Zecchin1, and Pedro J. Lee2
The need for more accurate simulation of transient pipe flow has seen a rising interest in unsteady friction models. Such models capture the dynamic wall shear effects within an accelerating (or decelerating) pipe flow. These models take the form of a convolution operator on the mean axial acceleration of the flow. Given the computational burden of the convolution calculation, computationally efficient approximate methods have been developed. These methods approximate the convolution kernel with a finite series of exponential functions. Such approximations can potentially lead to non-physical models that violate fundamental physical laws. This paper analyses these approximations with respect to the criteria of passivity (the physical models must dissipate energy). From this analysis, a sufficient condition for the strict passivity of the approximations is obtained.
File Size : 641,345 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 34th Congress - Brisbane (2011)
Article : THEME 4: Responding to Shifting Water Resources
Date Published : 01/07/2011
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