On December 29, 2024, the CR450 EMU prototype was officially released, marking a major breakthrough in the development of my country's new generation of 400 kilometers per hour EMU. Among them, "CR" is the English abbreviation of China Railway, and "450" is the speed grade code, which means that the test speed can reach 450 kilometers per hour and the operating speed is 400 kilometers per hour, making it the fastest high-speed train in the world.
The CR450 EMU prototype is composed of 8 cars and is internationally leading in major indicators such as operating speed, operating energy consumption, interior noise, and braking distance!
include:The braking distance is shorter, the operation stability is better, the vehicle running resistance is reduced by 22%/the weight is reduced by 10%, the noise in the vehicle is reduced by 2 decibels, the passenger room service space is increased by 4%, etc., while driving and control, driver intelligent interaction, safety monitoring, passenger intelligent services and other aspects are comprehensively upgraded.
So, how was CR450 developed?
The Institute of Mechanics of the Chinese Academy of Sciences also participated in the research and development of the CR450 EMU prototype, providing effective support especially in terms of aerodynamic shaping, safe operation in high winds, and noise-friendly and environmentally friendly design.
As train speeds increase, improvements in aerodynamic performance are critical to reducing energy consumption.
At a speed of 300 kilometers per hour, aerodynamic resistance accounts for more than 75% of the total resistance, and as the speed increases, the train power is mainly used to overcome aerodynamic resistance.
The CR450 EMU needs to reduce aerodynamic drag by 21-25% based on the existing Fuxing train.
To this end, the Institute of Mechanics of the Chinese Academy of Sciences uses the independently developed high-speed train two-way dynamic model test platform toCompleted the testing and evaluation of the aerodynamic performance of 7 CR450 high-speed train heads, providing quantitative support for the finalization of the CR450 model.
CR450 EMU prototype driving model test
Environmental wind is also a key factor affecting the further speed increase of high-speed trains. Due to the lightweight design goal, the CR450 high-speed train has higher requirements for its crosswind overturning resistance.
The Institute of Mechanics of the Chinese Academy of Sciences combines aerodynamics and vehicle dynamics theory,A systematic study was conducted on the operating safety of high-speed trains in the speed range of 350-450 kilometers per hour, and an evaluation index system for high-speed trains in windy environments was proposed, and a combined wind speed and direction threshold and wind speed limit operation plan were formulated.
Evolution of vortex on the leeward side of CR450 EMU in strong wind environment
As the speed increases, the noise problem becomes increasingly prominent.
Institute of Mechanics, Chinese Academy of Sciences establishedThe wheel-rail/aerodynamic noise simulation model was developed, the main line noise sources were quantitatively sorted, and a multi-source noise prediction model outside the vehicle was established., which provides a theoretical basis for EMU noise design and railway environmental noise prediction.
Quantitative comparison of sound source changes with velocity in different areas
These research results not only improve the performance of CR450 EMUs, but also lay a solid foundation for the future development of my country's high-speed rail technology.