Key Takeaways & Executive Findings
- •• Air blowing in the transition region (Scheme 1) at 0.1U achieves optimal noise reduction of 1.53 dB(A) by suppressing wake vortices. • Air blowing in the side edge area (Scheme 2) is effective across a wide speed range (0.1U–0.5U) for noise mitigation. • Air sucking is less effective than blowing, with noise reduction values below 0.84 dB(A). • Simultaneous reductions in aerodynamic noise and drag are possible with specific blowing/sucking configurations, offering design insights for low-noise and low-resistance HSMTs.
Abstract
The increasing aerodynamic noise caused by high-speed maglev trains (HSMTs) contributes substantially to environmental pollution and passenger discomfort. Numerical studies were performed to examine the effect of air blowing/sucking modes, positions and velocities on the flow field change and their potentials in mitigating the aerodynamic noise produced by HSMTs. The results indicate that the aerodynamic noise can be effectively mitigated by implementing air-blowing in the transition region between the streamlined tail nose and constant cross-sectional body (Scheme 1) and the wake vortex shedding area near the tail nose (Scheme 3) at speeds below 0.3U (train speed), as well as in the side edge area (Scheme 2) at various speeds (0.1U−0.5U), primarily due to the suppression in wake vortices. The optimal noise reduction value of 1.53 dB(A) is achieved when blowing in Scheme 1 at a speed of 0.1U, while the efficacy of the air-sucking mode is inferior with a smaller noise reduction value less than 0.84 dB(A). Additionally, simultaneous reductions in aerodynamic noise and drag can be achieved when sucking in Scheme 2 at speeds below 0.2U and blowing in Scheme 3 at speeds below 0.3U. These findings offer valuable insights for the application of active flow control technology in the design of low-resistance and low-noise HSMTs.
1. Introduction
The maglev train, a contemporary high-tech innovation, possesses enhanced speed capability due to its elimination of the wheel-rail adhesion constraint, making it a significant focus for future developments in rail transportation [1]. Previous studies indicated that high-speed operation in complex environment leads to a series of aerodynamic issues to rail transit vehicles [2−5]. As the speed of high-speed maglev trains (HSMTs) continues to increase, aerodynamic noise becomes predominant and increases significantly, demonstrating a proportional relationship to the 6th−8th power of the train speed. Excessive noise pollution diminishes passenger comfort and significantly affects the daily lives of nearby residents [6]. The noise level recorded for the TR08 HSMT reached 88 dB(A) at a speed of 350 km/h, greatly exceeding the environmental standard [7]. Consequently, aerodynamic noise has emerged as a significant impediment to the efficient and sustainable advancement of HSMTs. Additionally, the escalation in aerodynamic resistance induced by increasing speed leads to substantial energy consumption, which is also a critical aerodynamic issue that should be taken into account concurrently [8].
Numerous scholars have comprehensively investigated the train’s aerodynamic noise using field testing, model testing, and numerical simulations. KITAGAWA et al [9] and NAGAKURA [10] conducted a series of wind tunnel tests and field tests to identify the source of aerodynamic noise associated with Shinkansen trains. Findings revealed that the lower section of the train significantly contributes to trackside noise. However, the most efficient method to study the aeroacoustic characteristics of trains is through numerical simulations. IGLESIAS et al [11, 12] utilized a prediction model to anticipate the aerodynamic noise of pantographs and bogies, achieving a favorable agreement with the wind tunnel measurements. Similarly, LIANG et al [13] employed a numerical simulation method to estimate the aerodynamic noise in bogie regions. Their findings revealed that the presence of a cavity played a substantial role in the production of aerodynamic noise in this specific region. HE et al [14] also pointed out that the complex bogie components contributed a lot to the train's total aerodynamic noise, and the rear of the bogie cavity was a crucial area for the noise generation. KIM et al [15] conducted an investigation into the flow characteristics and acoustic impact of simplified pantographs and roof cavities using the IDDES turbulence model and the FW-H acoustic analogy. Predictions of the transient flow performance and far-field noise generated by pantographs were also conducted by several researchers [16−20]. ZHANG et al [21] introduced flow-guided structu...
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HUANG Sha, LIN Jin-rong, LI Zhi-wei, TAN Xiao-ming, BIN Xue-li, WANG Chen-ao, LIN Ren-kun (2025). Flow optimization and aerodynamic noise reduction of high-speed maglev trains based on air blowing/sucking. Journal of Central South University. https://doi.org/10.1007/s11771-025-6145-6
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Frequently Asked Questions
What is the optimal air blowing configuration for reducing aerodynamic noise in high-speed maglev trains?
The optimal configuration is air blowing in the transition region between the streamlined tail nose and constant cross-sectional body (Scheme 1) at a speed of 0.1U, achieving a noise reduction of 1.53 dB(A).
How does air sucking compare to air blowing in terms of noise reduction?
Air sucking is less effective than air blowing, with noise reduction values below 0.84 dB(A), whereas blowing can achieve up to 1.53 dB(A) reduction.
Can aerodynamic noise and drag be reduced simultaneously?
Yes, simultaneous reductions can be achieved when sucking in Scheme 2 at speeds below 0.2U and blowing in Scheme 3 at speeds below 0.3U.
What is the primary mechanism behind the noise reduction?
The primary mechanism is the suppression of wake vortices, which are major sources of aerodynamic noise in high-speed maglev trains.
What are the practical implications of this study?
The findings provide valuable insights for applying active flow control technology in the design of low-resistance and low-noise high-speed maglev trains, contributing to environmental sustainability and passenger comfort.
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