Multidisciplinary approach to railway pneumatic suspensions: pneumatic pipe modelling

Docquier, Nicolas [UCL] Fisette, Paul [UCL] Jeanmart, Hervé [UCL]

On the majority of modern railway vehicles, airspring are used for the secondary suspension, i.e. the suspension located between the bogie frame and the carbody. The airspring is connected with several other pneumatic components such as auxiliary tanks, pipes, valves, etc. Such a system can be analysed in a multidisciplinary approach by coupling a multibody model of the train with a detailed pneumatic model of the suspension. This paper presents and compares various modelling approach for the pneumatic suspension, focusing on the bellowpipe-tank subsystem. The pipe is described in more details distinguishing models with algebraic or differential equations and models that take compressible effects into acount or not. The various approaches are compared on a simple excitation test and confronted to a reference solution obtained with the commercial FLUENT software. It is shown that the compressible effect can not always be neglected. The influence of the pipe length is also presented.