Shock waves often occur in hydraulic systems, including pipes, valves and pumps due to quickly closing valves. As a result, cavitation and air-release-related bubbles are created due to local pressures in the liquid dropping below the liquid saturation pressure. The developed model, combining fluid dynamics of the flow and a numerical model of caviatation and air release, computes all flow characteristics, including the behaviour of pressure, mass flow and volumetric void fractions of vapour and air in the liquid. The occurrence of the shock waves and their relation to cavitation are explained and discussed in detail. To avoid numerical oscillations and to maintain a high numerical accuracy in shock wave flows, the total variation diminishing method is applied to discretize the equation system. Furthermore, various limiters are used to prevent the numerical solutions from overshooting or undershooting. Finally, the computational results are compared with the experimental data measured on a single pipeline terminated with a valve. This comparison shows very good agreement with the experiment.
|Number of pages||21|
|Journal||Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering|
|Publication status||Published - 2001|