Key Takeaways & Executive Findings
- •• Full bogie fairing (FBF) yields a more uniform pressure distribution in the bogie region compared to baseline fairing. • Wheelset rotation reduces drag by 6.38% with baseline fairing but increases drag by 3.5% with full fairing. • In FBF configuration, aerodynamic drag originates primarily from wheelsets; rotating rear wheelset increases drag by 18.8%. • The study underscores the necessity of accounting for wheelset rotation in aerodynamic optimization of high-speed train bogies.
Abstract
Aerodynamic drag is the dominant factor contributing to energy consumption as the operational speed of high-speed trains increases, necessitating effective aerodynamic optimization strategies. This study investigates the aerodynamic characteristics of the bogie region under two bogie fairing configurations: baseline bogie fairing (BBF) and full bogie fairing (FBF). Both stationary and rotating wheelset conditions are considered. Wind tunnel experiments were conducted on a full-scale bogie model equipped with a wheelset drive system to simulate wheelset rotation. Additionally, numerical simulations were employed to analyze flow structures. Results indicate that the FBF configuration promotes a more uniform front-to-rear pressure distribution in the bogie region. The rotation of the wheelset notably affects the airflow near the wheels and extends its influence throughout the entire bogie region. Specifically, wheelset rotation reduces drag by 6.38% in the BBF configuration but increases drag by 3.5% in the FBF configuration. Further analysis reveals that, in the FBF configuration, aerodynamic drag primarily originates from the wheelsets. The rotating wheelset increases the aerodynamic drag by 18.8% for the rear wheelset, which is attributed to the shift in the pressure curve on the wheelset in the rotating direction. Therefore, the impact of wheelset rotation on aerodynamic characteristics should not be overlooked.
1. Introduction
High-speed trains (HSTs) are designed to transport passengers efficiently between cities. They offer advantages such as high speed, improved comfort, and reduced environmental impact [1]. With rapid economic growth and increasing public demand for convenient travel, there is an urgent need to further enhance the operational speeds of HSTs. However, higher speeds intensify turbulent disturbances around the train, making aerodynamic issues more pronounced compared to lower speed [2]. During the speed-holding phase, approximately 60% of the traction energy obtained from the pantograph is consumed to overcome running resistance [3]. At an operating speed of 300 km/h, aerodynamic drag accounts for more than 75% of the total running resistance. Excessive aerodynamic drag not only results in energy wastage but also reduces economic efficiency. Therefore, optimizing aerodynamic design to minimize drag is a crucial technological strategy for increasing the operational speeds of HSTs.
Bogies, located beneath HSTs, have complex geometric configurations. As airflow passes through the bogie region, aerodynamic effects and flow separations generate intricate turbulent structures. Research on airflow beneath HSTs has identified the bogie region as a significant source of aerodynamic drag [4]. The underbody structures of the German Inter-City-Express 3 (ICE3) trains account for approximately 44% of the total aerodynamic drag [5]. Numerical simulations of an eight-car marshaled train, including bogies, pantographs, and ventilation covers, showed that the bogie region contributed 27.4% of the total aerodynamic drag at 350 km/h [6]. When comparing conditions with and without bogies, the presence of bogies nearly doubled the aerodynamic drag [7]. One effective strategy for reducing the aerodynamic drag in the bogie region involves optimizing structural design to guide airflow into desired flow structures. JIANG et al [8] used a two-multistage wing deflector to control underbody flow, achieving a 4.26% reduction in aerodynamic drag at 400 km/h. In addition, the impact of bogie fairing configurations on aerodynamic drag was studied. Full-scale tests on the Italian ETR 500 HSTs demonstrated that the addition of bogie fairings reduced aerodynamic drag by approximately 10% [9]. WANG et al [10] investigated aerodynamic performance using three skirt bogie fairings (without, half-size, and full-size) on a three-car marshaling train, finding that the full-size skirt bogie fairing reduced aerodynamic drag by 27.1% compared to that without fairing. Smoothing treatments of the bogie region reduced the turbulence intensity in the downstream zones, which decreases aerodynamic drag significantly [11]. The latest research is presented in this paper.
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ZHENG Ze-yuan, WANG Tian-tian, WANG Yu, SHI Fang-cheng, FENG Yong-hua, LIU Hong-kang, ZHAO Chang-long, JIANG Chen (2025). Aerodynamic characteristics on a full-scale high-speed train bogie with rotating wheelsets. Journal of Central South University. https://doi.org/10.1007/s11771-025-6137-6
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Frequently Asked Questions
What is the main objective of this study?
The study investigates the aerodynamic characteristics of a full-scale high-speed train bogie under two fairing configurations (baseline and full bogie fairing) with stationary and rotating wheelsets, to understand the impact of wheelset rotation on drag and pressure distribution.
How does wheelset rotation affect aerodynamic drag in the bogie region?
Wheelset rotation reduces drag by 6.38% with baseline bogie fairing but increases drag by 3.5% with full bogie fairing. In the full fairing configuration, the rotating rear wheelset increases drag by 18.8% due to a shift in the pressure curve.
What experimental and numerical methods were used?
Wind tunnel experiments were conducted on a full-scale bogie model with a wheelset drive system to simulate rotation, and numerical simulations were employed to analyze flow structures.
Why is the bogie region important for high-speed train aerodynamics?
The bogie region is a significant source of aerodynamic drag, contributing up to 27.4% of total drag at 350 km/h in some studies. Optimizing its design can lead to substantial energy savings.
What are the practical implications of this research?
The findings highlight that wheelset rotation must be considered in aerodynamic optimization of bogie fairings, as it can either reduce or increase drag depending on the fairing configuration, affecting energy efficiency and operational costs.
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