Scientists unveil 'silencer' to fix Maglev train tunnel boom
What's the story
China's latest prototype magnetic levitation (maglev) train, capable of speeds up to 600km/h, is facing a major engineering challenge: "tunnel boom." This phenomenon occurs when high-speed trains enter and exit tunnels, creating low-frequency shock waves due to compressed air in front of them. These shock waves can be disruptive and even damaging to structures. However, researchers have found a potential solution by installing innovative soundproofing buffers at tunnel entrances.
Solution
New soundproofing buffers can reduce shock waves by 96%
The new soundproofing buffers, which are porous and 100 meters long, can reduce shock waves by up to 96%. This could greatly improve operational safety and passenger comfort while also protecting nearby animals. The problem of tunnel boom was already known for conventional high-speed trains (up to 350km/h). However, it gets worse with faster trains as the strength of the shock wave increases rapidly.
Technology
What is magnetic levitation?
Magnetic levitation, or maglev, is a technology that uses magnetic force to lift and propel a train. It can travel at speeds of up to 600km/h without the friction of wheels against tracks. There are two types of suspension systems for maglev trains: electromagnetic suspension (EMS) and electrodynamic suspension (EDS). Both systems use electromagnets or superconducting coils to create repulsive and attractive forces that enable levitation.
Development
China introduced high-speed maglev trains in 2004
China introduced high-speed maglev trains in 2004, connecting Pudong airport and Shanghai at a speed of 460km/h. Despite the initial success, the focus shifted to conventional high-speed rail development. However, under state-owned manufacturer CRRC, maglev trains are making a comeback with new models launched in 2021. A future line connecting Beijing and Shanghai is expected to cut travel time from 4.5 hours to just 2.5 hours.