Title:Wave Propagation in Periodically Excited Fluid Transmission Lines with a Nonlinear Compressibility LawAuthor(s):Bernhard ManhartsgruberAbstract:Pipelines filled with a weakly compressible fluid such as mineral oil or water play an important role in many fields of technology such as internal combustion engines or hydraulic drives. A number of interesting problems such as the prediction of pressure ripples for piston pumps or the simulation of fuel injections systems at a single operating point share the property of periodic boundary conditions. The phenomenon of wave propagation in transmission lines is well understood in the case of a weakly compressible fluid with a linear material law. For this type of problem, the periodic case can be treated with high computational efficiency by using transcendental transfer functions in the frequency domain. This paper aims at the computation of pressure and flow waves arising in liquid transmission lines with periodic pressure and/or flow boundary conditions and a nonlinear law of liquid compressibility. The nonlinearity is due to the presence of small gas bubbles in the liquid. This condition frequently occurs in the low pressure part of fluid power systems where dissolved air is released. An isothermal behaviour of the gas bubbles is assumed in this paper for computational simplicity. The validity of this assumption or more likely the need for a refined model with a detailed description of the gas behaviour will be the focus of experiments in the near future.Booktitle:Proceedings MATHMOD 09 Vienna - Full Papers CD VolumeEditor(s):I. Troch, F. BreiteneckerISBN:978-3-901608-35-3Page Reference:9 page(s)Publishing:2/2009