Discussion and Closure: Comparison of Methods for Predicting Deficient-Network Performance

Abstract

The authors have shed some much needed light on the poorly understood and much neglected issue of the pressuredriven analysis of water distribution networks with particular reference to less than fully satisfactory performance (Lumbers 1996). The authors' algorithm for network analysis with pressure-dependent nodal outflows appears in essence to be an iterative two-phase formulation in which each major iteration consists of a traditional demand-driven analysis followed by a formula-based calculation of improved nodal outflows. Taken together with Chandapillai (1991), the aforementioned twolevel iterative technique is useful for appraising the performance of distribution networks if nodal outflows and pressures are less than fully satisfactory. Such a situation is commonly encountered in distribution network reliability analysis (Tanyimboh and Templeman 1993, 1994, 1995). The discussers' preliminary results would appear to suggest that further research into algorithms for pressure-driven simulation is required to improve the computational efficiency of the approach. Nevertheless, the authors have presented some interesting results worth commenting on. Eq. (6), a special case of (8) (Chandapillai 1991), is quite useful