Analysis of wave damping in pipeline having different pipe materials configuration under water hammer conditions

Hydraulic transient occurs whenever there is a sudden change in the flow velocity resulting in variation of pressure and flow in a water conductor system . Experiments have been conducted in a straight pipeline having material of Mild Steel (MS) and Glass Fibre Reinforced Plastic (GRP) pipelines and their combined configurations. From experiments, it has been observed that there is a smooth and strong damping of pressure waves in the pipeline system. Experimental results were compared with results obtained for classical water hammer equations solved in MATLAB and analyzed that there are several dissipative factors, other than fluid viscosity, responsible for strong damping of pressure wave amplitude. Further, an improvement in the governing equation of water hammer in a closed conduit was proposed by incorporating a different wave damping coefficient (a). The modified governing equations have been solved for each water hammer cycle using MATLAB. The numerical simulation results show that proposed approach gives better agreements between the experimental and computational results for all investigated cases.