Modeling the dynamics of flow in gas pipelines

The transfer function method is presented to model periodic flows in water pipelines. Laplace transforms are used to transform the governing equations for transient flows and then converted into the time domain by applying the convolution theorem. The accuracy and computational efficiency of the proposed method are evaluated by comparing the computed results with those obtained by the method of characteristics for series piping systems with different pipe diameters, lengths and wave speeds and also changing the amplitude and frequencies of the periodic oscillation. One branching piping system is also considered. The effect of the variation of computational time intervals is investigated by analysing a series piping system. The present results compare satisfactorily with those obtained by the method of characteristics for periodic flows. The proposed method may be used for online applications, such as for operation and control, state estimation and for leak or blockage detection in water pipelines.

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“…where F H2,H1 , F H2,Q2 , F Q1,Q2 and F Q1,H1 are transfer functions given by (Reddy et al 2006, Kralik et al 1984)…”

Section: Methodsmentioning

confidence: 99%

Modelling of periodic flows in pipelines by transfer function method

Reddy

Chaudhry

Mohapatra

2010

Journal of Hydraulic Research

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“…In this paper, Reddy et al [2006] analytically invert the rational transfer function approximations proposed Kralik et al [1984] to develop a discrete time-domain network model. Case study specific matrices are constructed to relate the fluid variables at the pipe end points.…”

Section: Muto and Kaneimentioning

confidence: 99%

Transient Modeling of Arbitrary Pipe Networks by a Laplace-Domain Admittance Matrix

et al. 2009

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An alternative to modeling of the transient behavior of pipeline systems in the time-domain is to model these systems in the frequencydomain using Laplace transform techniques. Despite the ability of current methods to deal with many different hydraulic element types, a limitation with almost all frequency-domain methods for pipeline networks is that they are only able to deal with systems of a certain class of configuration, namely, networks not containing second order loops. This paper addresses this limitation by utilizing graph theoretic concepts to derive a Laplace-domain network admittance matrix relating the nodal variables of pressure and demand for a network comprised of pipes, junctions and reservoirs. The adopted framework allows complete flexibility with regard to the topological structure of a network and as such, it provides an extremely useful general basis for modeling the frequency-domain behavior of pipe networks. Numerical examples are given for a 7-pipe and 51-pipe network, demonstrating the utility of the method.

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“…Node The point of the network where the flow of gas branches; the point being caused by space discretization of very long tubes (see [1]). …”

Section: B System Decompositionmentioning

confidence: 99%

“…Two different concepts of space discretization have been presented in [1]. In the first one the state variables, pressure and flow, are related to the nodes-see Fig.…”

Section: A Space Discretizationmentioning

confidence: 99%