UBC Theses and Dissertations
Analysis of fluid transients in large distribution networks Karney, Bryan William
It is well known that the pressures generated during transient conditions should be an important consideration when pipeline systems are being designed or constructed. If the size and strength of the required pipe is to be rationally selected, if the surge suppression equipment is to be logically sized and if system operating rules are to be intelligently specified, reliable transient analysis is essential. The aim of this research has been to develop a general, efficient and reliable algorithm for computing the response of large distribution systems to rapid transient conditions. Although further refinement and verification work is still required, it is considered that this goal has been achieved. Significantly, the algorithm is general, since a wider class of networks can be analyzed than was previously possible. The program is also efficient, since the solution of many of the network boundary conditions is made explicit for the first time and because computer storage is conserved in the program implementation. Finally, the program is reliable, since a number of numerical experiments have proven its correctness. Specifically, the solution procedure for obtaining the transient response of large networks includes the following new features: a coupling of the steady and unsteady parts of the analysis avoids duplication and improves program efficiency; a general network and boundary condition classification system which permits networks with any reasonable topology to be analyzed; solution procedures for many common network boundary conditions are made explicit or put in a form which allows efficient numerical calculation; and, finally an automatic algorithm for selecting the time step and dividing the network pipes into an integer number of reaches. All of these elements combine to produce efficient and accurate transient analysis of large distribution systems. In summary, the developed algorithm allows comprehensive transient analysis of networks having arbitrary geometry to be performed. The networks may include any general combinations of hydraulic devices and no restriction is placed on either the number of boundary conditions or pipes that connect to a given node or the number of sections found in any pipe in the network. Procedures have been utilized which keep data requirements to a minimum despite the general nature of the problem being solved. Finally, the program has been carefully tested and compared with known solutions for simple pipelines with very good agreement being observed.
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