Abstract
Flexible hosepipes are often used in an oil-hydraulic system. In highly pressurized hydraulic systems, big changes of pressure and flow rate in the components cause oscillation and deformation of the flexible hosepipe itself. Those phenomena may cause destruction of the hosepipes if a natural frequency of a valve should coincide with that of a hosepipe system. Some studies have been performed on pressure propagation in the hosepipes, which were conducted by considering the dynamic characteristics of the internal fluid combined with the characteristics of the hosepipe wall. However, these models could not explain the mechanism of the oscillation and deformation. From a viewpoint of safety, the mathematical model must represent such mechanism. The objective of this study is to propose the mathematical model of the flexible hosepipes, which contains the characteristics of the internal fluid, a flexible hosepipe itself and their interactions. All the numerical results were compared with experimental results. The bondgraph method was used for modeling.
