Blowing away drag for maglev trains
Blowing away drag for maglev trains lead image
Modern maglev trains can rocket across land up to 600 kilometers per hour using electromagnets that levitate the train and propel it forward without the burden of friction from the rail. With little associated noise, a smooth ride, and unlikely risk of derailment, maglev trains promise a comfortable and efficient transportation method.
Yet, at such high speeds, drag becomes a significant force that conventional reduction methods like an optimized aerodynamic shape cannot fully overcome. Che et al. simulated the impact of strategic air-blowing on drag reduction, potentially creating more energy-efficient, and even faster, transportation.
“For trains operating at high speeds in the dense atmospheric layer near the Earth’s surface, whether they are conventional rail or maglev trains, aerodynamic drag remains a crucial issue,” said author Zheng-Wei Chen. “Blowing air can disrupt the near-wall fluid motion, leading to the formation of numerous small-scale vortical structures. It can weaken the strength of the flow-induced vortices and push them away from the surface.”
The team investigated the drag reduction associated with blowing air at different speeds and directions. By examining the wake flow, the team identified the optimal orientation for air-blowing and analyzed the underlying mechanisms behind this phenomenon to inform future work.
“I believe the key point of blowing control technology lies in ‘active control,’ aiming to develop a systematic and intelligent control system that can optimize drag reduction effects based on the train’s operating environment,” said Chen. “In future research, I intend to conduct multi-parameter analyses of blowing – including speed, direction, position, outlet configuration, energy efficiency, etc. – to establish a comprehensive framework and provide ample theoretical support for achieving systematic and intelligent control.”
Source: “Research on the impact of air-blowing on aerodynamic drag reduction and wake characteristics of a high-speed maglev train,” by Zheng-Xin Che, Zheng-Wei Chen, Yi-Qing Ni, Sha Huang, and Zhi-Wei Li, Physics of Fluids (2023). The article can be accessed at https://doi.org/10.1063/5.0175323 .
