Water Journal : Current May 2017
www.awa.asn.au 113 JUDGING PERFORMANCE GA was found to be a time-efficient alternative to the manual adjustment of friction factors. However, the performance of GA was highly dependent on the input parameters, such as the provided range of friction factors for each pipe group. GA provided an answer out of many possibilities that fulfilled the tolerance requirements. However, when the provided friction ranges were too wide, unrealistic solutions were considered. Therefore, engineering judgement was required to ensure only realistic friction factor ranges for pipe groups are used. If the calibration results were unsatisfactory with those constraints, it was necessary to manually identify local network restrictions and adjust the model accordingly. The calibrated model will be used to locate underperforming sections of the network for field investigations prior to augmenting or renewing assets. It will also guide the refinement of the capital works program and provide confidence in lowering DMA pressures to reduce leakage while ensuring the desired level of service will still be met. Ken Goraya is responsible for Unitywater’s development of network master plans. Joseph Xu is a network modelling engineer with Unitywater. To read the full article, visit the Water e-Journal at bit.ly/water_ejournal Noosa Hydrant Replacement Good calibration requires stress testing the network with high flows such as hydrant flow tests.
Current Feb 2017
Current August 2017