%0 Journal Article
%T Hydraulic Analysis of Water Distribution Network Using Shuffled Complex Evolution
%A Naser Moosavian
%A Mohammad Reza Jaefarzadeh
%J Journal of Fluids
%D 2014
%R 10.1155/2014/979706
%X Hydraulic analysis of water distribution networks is an important problem in civil engineering. A widely used approach in steady-state analysis of water distribution networks is the global gradient algorithm (GGA). However, when the GGA is applied to solve these networks, zero flows cause a computation failure. On the other hand, there are different mathematical formulations for hydraulic analysis under pressure-driven demand and leakage simulation. This paper introduces an optimization model for the hydraulic analysis of water distribution networks using a metaheuristic method called shuffled complex evolution (SCE) algorithm. In this method, applying if-then rules in the optimization model is a simple way in handling pressure-driven demand and leakage simulation, and there is no need for an initial solution vector which must be chosen carefully in many other procedures if numerical convergence is to be achieved. The overall results indicate that the proposed method has the capability of handling various pipe networks problems without changing in model or mathematical formulation. Application of SCE in optimization model can lead to accurate solutions in pipes with zero flows. Finally, it can be concluded that the proposed method is a suitable alternative optimizer challenging other methods especially in terms of accuracy. 1. Introduction A water distribution network is composed of an edge set consisting of pumps, pipes, valves, and a node set consisting of reservoirs and pipe intersections [1]. The equations governing the flows and heads in a water distribution system are nonlinear, and often a Newton iterative solution algorithm is used in which a linearized set of equations is solved at each iteration [2]. The Newton-based global gradient algorithm (GGA) is a popular method used in solving the water distribution System (WDS) equations [3]. Given the nonlinearity of the system of equations, the Newton-based computation of the solution involves an iterative two-step process. The first step includes computing the state variable update, which requires the solution of linear system derived from the Jacobian of the WDS equations. The second step deals with updating estimates of the state variables. The first step is typically the most computationally expensive process within the GGA [4]. Furthermore, some of the pipes in a network, in which the head losses are modeled by the Hazen-Williams formula, have zero flows. In that case, a key matrix in the method becomes singular and the matrix to be inverted becomes ill conditioned [2]. As a result a failure
%U http://www.hindawi.com/journals/fluids/2014/979706/