Pitfalls in Pipe Network Analysis Techniques

Abstract

Pipe network analysis, wherein the steady state flows and the hydraulic heads are determined in a pipe network, is a basic engineering tool. Application of commonly used iterative solution techniques, particularly for problems of engineering significance, have potential subtleties and pitfalls. Different iteration techniques have difference convergence properties. A simple network is used to demonstrate that linear iteration techniques may never converge for some system characteristics. Different criteria for terminating iterative procedures can be used. Different criteria, as demonstrated by example for a large scale network, can result in significantly different solutions at the point of iteration termination. Multiple solutions may exist in networks with nonunique element characteristics or multiple operating modes. A simple network with two pressure reducing valves and three pumps provides an example. Thus, application of traditional network analysis techniques may not be as straightforward as might appear.