Aerodynamic braking device for high-speed trains: Design,simulation and experiment

This paper proposes the design of an aerodynamic braking device for a high-speed train. The design is based on the parameters of the high-speed train and the working principles of airplane wings. The proposed device is a unidirectional opening model driven by hydraulics. The prototype uses hard-wired signals to transmit braking commands on eight levels. The important characteristics of the device include a synchronous action and a fault-oriented security design. Its functions include service braking, gradual braking, emergency braking and self-checking. Simulation results show that deceleration in the high-speed zone between 250 and 500 km/h can be improved by between 8 and 60%. When the train runs at 500 km/h, the braking deceleration rate can be improved by 0.12 m/s². The simulation results are found to agree with wind tunnel test results. The braking characteristics are also investigated using a test bed, which mimics the aerodynamic load exerted on the prototype when the train is running between 0 and 550 km/h. It is clearly demonstrated that the proposed principle of the aerodynamic braking system is feasible and its design scheme is reasonable. The aerodynamic braking device can survive a 50,000 N aerodynamic load, and the time taken to achieve the maximum braking capacity, which is the time taken to take the brake panel from its closed position of −5° to the maximum angle of 75°, is less than 3 s. The proposed prototype therefore offers an important step in the design of practical systems.