Key Takeaways & Executive Findings
- •• Lateral translation of 30 mm without crosswinds induces synchronous resonance in side and bottom gaps, causing the worst aerodynamic performance. • Under crosswind conditions, a lateral translation of 40 mm maximizes peak pressure fluctuations and turbulent kinetic energy, leading to poorest aerodynamic stability. • The study validates a numerical simulation method against wind tunnel tests, enabling accurate prediction of aerodynamic behavior in superconducting maglev systems. • Findings provide critical guidance for operational safety and design improvements to mitigate aerodynamic instability in superconducting maglev trains.
Abstract
Abstract: Irregularities in the track and uneven forces acting on the train can cause shifts in the position of the superconducting magnetic levitation train relative to the track during operation. These shifts lead to asymmetries in the flow field structure on both sides of the narrow suspension gap, resulting in instability and deterioration of the train’s aerodynamic characteristics, significantly impacting its operational safety. In this study, we firstly validate the aerodynamic characteristics of the superconducting magnetic levitation system by developing a numerical simulation method based on wind tunnel test results. We then investigate the influence of lateral translation parameters on the train’s aerodynamic performance under conditions both with and without crosswinds. We aim to clarify the evolution mechanism of the flow field characteristics under the coupling effect between the train and the U-shaped track and to identify the most unfavorable operational parameters contributing to the deterioration of the train’s aerodynamic properties. The findings show that, without crosswinds, a lateral translation of 30 mm causes a synchronous resonance phenomenon at the side and bottom gaps of the train-track coupling, leading to the worst aerodynamic performance. Under crosswind conditions, a lateral translation of 40 mm maximizes peak pressure fluctuations and average turbulent kinetic energy around the train, resulting in the poorest aerodynamic performance. This research provides theoretical support for enhancing the operational stability of superconducting magnetic levitation trains.
1. Introduction
The superconducting magnetic levitation system is currently the only confirmed practical engineering magnetic levitation system capable of operating at a speed of 600 km/h [1, 2]. However, owing to differences in levitation methods, the aerodynamic challenges it faces differ somewhat from those of conventional electromagnetic levitation systems. The superconducting magnetic levitation (maglev) train operates within a semi-enclosed space formed by U-shaped tracks. Electromagnetic force control is a passive control system that adjusts the variation in the levitation gap. The levitation gap between the train and the sides of the U-shaped track can reach up to 55 mm, while the gap between the train and the bottom of the track can reach up to 100 mm, which is significantly larger than the minimum levitation gap of 10 mm in conventional magnetic levitation systems [3, 4]. Consequently, under strong winds, significant fluctuations in aerodynamic forces, or when passing through tunnels, sudden changes in the flow field structure can cause the train to experience lateral movement, worsening the instability of the flow field around the train. In extreme cases, this may lead to contact between the train and the track [5−7]. These unique aerodynamic challenges underscore the necessity for systematic research on maglev systems, particularly under dynamic operational conditions.
Since the concept of maglev trains was introduced, studies have focused on their aerodynamic challenges. These studies primarily address flow control, drag reduction, noise reduction, aerodynamic performance during passing, operational safety in strong wind conditions, and the aerodynamic behavior of train/tunnel coupling. However, research on variations in train operating posture remains relatively limited [8−12]. KLOPFER et al [13] used the RANS model to study the evolution of the flow field structure of superconducting maglev trains operating on U-shaped tracks. BARROWS et al [14] used a separated vortex model to systematically simulate the aerodynamic drag and lift characteristics of superconducting maglev trains. ZHANG et al [15] proposed a novel bionic elytron installed on the pantograph areas of an eight-car grouping high-speed train to smooth the flow based on the biological pattern of coleopteran. JIANG et al [16] iteratively designed the bogies in a streamlined shape and combined them with the bottom deflector.
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ZHANG Lei, PAN Shen-gong, LIN Tong-tong, YU Qing-song, WANG Tian-tian, YANG Ming-zhi, LIU Dong-run, XU Shu (2025). Effects of lateral translation on aerodynamic characteristics of superconducting maglev trains. Journal of Central South University. https://doi.org/10.1007/s11771-025-6042-z
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Frequently Asked Questions
What is the effect of lateral translation on superconducting maglev train aerodynamics?
Lateral translation causes asymmetries in the flow field around the train, leading to instability and deterioration of aerodynamic performance. Without crosswinds, a 30 mm translation induces synchronous resonance in side and bottom gaps, while under crosswinds, a 40 mm translation maximizes pressure fluctuations and turbulent kinetic energy.
How was the aerodynamic performance of the maglev train validated?
The study developed a numerical simulation method based on wind tunnel test results to validate the aerodynamic characteristics of the superconducting magnetic levitation system.
What are the most unfavorable lateral translation parameters?
Without crosswinds, a lateral translation of 30 mm results in the worst aerodynamic performance. Under crosswind conditions, a lateral translation of 40 mm leads to the poorest aerodynamic performance.
Why is the superconducting maglev train's aerodynamic behavior unique?
The superconducting maglev train operates in a semi-enclosed U-shaped track with larger levitation gaps compared to conventional maglev systems, making it more susceptible to lateral movements and flow field instabilities under strong winds or dynamic conditions.
What is the significance of this research?
The research provides theoretical support for enhancing the operational stability of superconducting magnetic levitation trains by identifying critical lateral translation parameters that affect aerodynamic performance, aiding in design and safety improvements.
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