The application of aerodynamic brake for high-speed trains

The braking distance for high-speed trains (HST) operating over 200 km/h takes roughly over 6000 m and 1 minute 40 seconds. In an emergency situation, both braking distance and stopping time are too high. Reducing the time and the distance for braking for such trains will be beneficial for passengers' safety and railway system management. A number of studies have been conducted to develop a better braking system based on mechanical or electromechanical technologies to overcome this issue. In this study, computational fluid dynamics (CFD) analysis are conducted by designing prototypes of aerodynamic brakes inspired by commercial aircrafts' flaps. Limited studies have been performed in implementing an aerodynamic brake in the high-speed trains. The primary emphasis of this study is to examine the argumentation on an aerodynamic performance by mounting the aerodynamic brake on HSTs to find out its effectiveness in terms of energy saving. A full-scale model of HST was analyzed in this study by varying velocities (200 km/h to 400 km/h), and the operating angles (35 degrees to 55 degrees). The results show that aerodynamic brakes can reduce the braking distance by 2.53 % and 1.56 % for when using the commercial and emergent braking, respectively.