Authors' original experiments featuring waterhammer in viscoelastic pipes is presented in which the effects of pipe-wall viscoelasticity on waterhammer pressures are investigated. A large-scale pipeline apparatus (industrial size) made of polyvinyl chloride (PVC) at Deltares, Delft, The Netherlands, has been used to carry out waterhammer experiments. Tests have been conducted in a reservoir-pipeline-valve system consisting of a long viscoelastic pipeline and two short steel pipes placed upstream and downstream of the main pipe. Rapid closure of a manually operated valve at the downstream end generates waterhammer. Repeated measurements at several positions along the pipeline have been recorded; these are plotted in figures and appropriately interpreted. Obtained results will serve for unsteady skin friction model validation studies in PVC pipelines.
COBISS.SI-ID: 13180443
Hydraulic transients are flow disturbances caused by a change from one steady state to another. Transients can disturb overall operation of the plant and damage the system components. Parameters that define the extent of the analysis, modelling and solution methods are covered. Transient analysis in Toro III HPP is presented as a case study. Preliminary transient analysis was performed using both analytical equations and in-house computer programme. Detailed transient analysis was performed using commercial software package SIMSEN that includes a number of hydraulic and electrical components. The pakage incorporates standard steady state skin friction model. Calculated and measured results for two normal operating regimes (slow transients) were compared: (1) closure of the the safety butterfly valve and (2) load rejection of two turbines from full load. Computational results agree well with the measured results. For relatively slow transients the steady state skin friction model is appropriate.
COBISS.SI-ID: 13183003