Development of a numerical model of railway air brake and validation against experimental data

The paper presents a model for the pneumatic part of UIC air brake, aiming at the prediction of the dynamics of compressed air in main braking pipe and braking cylinders. A lumped parameter scheme, based on an equivalent electrical circuit, is used to model the main braking pipe; the proposed scheme allows venting the pipe from different positions. Pressure build-up in braking cylinders is de-termined by the dynamics of pressure drop in main braking pipe and by the crossing of pressure thresholds. Time histories of pressure drop in main braking pipe and pressure build-up in braking cylinders were compared with experimental data collected with an indoor test facility to tune some of the model parameters and to validate the model itself.