An approach for simulating the air brake system of long freight trains based on fluid dynamics

Abstract Air brake systems are critical equipment for railway trains, which affects the running safety of trains significantly. To study air braking characteristics long freight , an approach simulating based on fluid dynamics theory was proposed. The structures and working mechanisms locomotive wagon brakes introduced, mathematical models pipes, valves, reservoirs or chambers, cylinders, etc., presented. Besides, dynamic motions parts in main valve considered. simulation model whole system is then formulated, solving method finite-difference used. New efficient pipe boundary conditions without iterations developed pipes branch can achieve higher computational efficiency. proposed validated by comparing with published measured data. Simulation results different train formations indicate that consider behavior recommended predicting under service conditions.