Low Frequency Correction of a Multi-degrees-of-freedom Model for Hydraulic Pipeline Systems

For hydraulic pipeline systems, a multi-degrees-of-freedom model is developed from the modal decomposition of the transfer function between flow rate excitation and pressure response. Eigenvectors are taken from the undamped case. Natural frequencies and damping ratios are calculated from modal approximations of the individual pipelines with single frequency approximations at the pipeline system resonances in the low frequency range. The multi-degrees-of-freedom pipeline system model is rebuilt from its modal description and evaluated for a network that connects a pump with two closed volumes.