Pipe resistance coefficients identification of water networks considering solvable conditions

To make hydraulic models more accurate and realistic, this paper proposes a method to identify pipe resistance coefficients (PRCs) by using the measured heads at partial nodes. A successive linearization method is adopted to solve for the pipe flows, node heads, and PRCs. Based on the matrix analysis theory, the relationships among the number and location of measurement sites, number of hydraulic conditions (HCs), and solvable condition of PRC identification are established. The proposed method can identify all the PRCs when a solvable condition can be satisfied. In addition, the analysis process can be used as a tool to evaluate whether a given arrangement of measurement sites can meet the solvable condition of PRC identification, and to determine the minimum number of HCs. The performed case studies verified the feasibility of the proposed method, and the determined accuracy of PRC identification was noted to satisfy the actual engineering requirements.