Research on friction factors calibration of water distribution system

Some approaches were proposed for improving the uniqueness and stability of the calibration problem solution for water distribution system.The sensitivity of the nodal pressures to the variation of roughness was analyzed and the sensitive nodes were chosen as pressure measuring point from which preferable calibration data can be collected under the condition of the given nodal demand.The new grouping method that calibrated the chosen sensitive links and the grouped other links was adopted for reducing the number of calibration variables.Multi-mode model was analyzed to collect more data for calibration.Empirical friction factors were estimated using all information available,then were utilized by ant colony algorithms to improve the convergence of optimization.Case study showed that the hydraulic model calibrated by the mentioned methods gave perfect matching between actual and computed pressure values.