Modeling and simulation of low pressure oil-hydraulic pipeline transients

In order to predict more accurately the pressure transients accompanying air release and vaporous cavitation inside oil-hydraulic low pressure pipelines, a new method using genetic algorithms (GAs) for parameter identification is described. A mathematical model for pressure and flow transients is presented in which models of vaporous cavitation and dynamic air release and re-solution are incorporated. This model enables the prediction of both the vaporous cavitation and the air bubble volumes in the pipeline during the transients following a sudden cut-off of the flow. The accurate prediction of behavior largely depends on three generally unknown parameters required by the model, namely: the initial air bubble volume in the oil, and the air release and re-solution time constants. Through the use of the GAs, these parameters can be identified. Predicted results and experimental data show close correspondence.

► A mathematical model for fluid transients in a low pressure pipeline is presented.
► The model enables prediction of cavitation and bubble volumes during the transients.
► By using GAs, the unknown parameters in the mathematical model can be identified.
► The transients accompanying cavitation and air bubbles were simulated and tested.
► Good agreements were shown between the predicted results and experimental data.