Leakage in transmission pipelines and water distribution networks causes water and energy loss and reduces water quality. The accuracy of leakage detection using transient-based methods depends on several factors. This study investigated the sensitivity of location and size of leaks in simple polyethylene transmission pipelines to dynamic parameters, flow regime, sample size, spatial-step increment, and leak size and location. For this purpose, a hydraulic transient solver was first developed to take into account the dynamic effects of unsteady friction, viscoelasticity of the pipe wall, and the leak. The leakage was assumed to function with a quasi-normal distribution around its real location to reduce the problem dimensionality and unnecessary computations. This approach was evaluated based on experimental transient data in which leaks were simulated in different sizes and locations. Results revealed that the hydraulic transient model that includes only viscoelasticity effects could pinpoint leakage characteristics. The sample size evaluation indicated that half and a single period of the pressure signal are sufficient to determine the leakage location and size in simple viscoelastic transmission pipelines, respectively. The optimal ratio of the spatial-step to pipe length (Δx/L) was 0.025.
Sensitivity analysis of leak detection and sizing in the viscoelastic pipeline.
Leakage simulate using a new approach with a quasi-normal distribution function.
Development of an experimental transient model to evaluate the proposed approach.