Impact of the bogies and cavities on the aerodynamic behaviour of a high-speed train. An IDDES study
Journal article, 2020

This study investigates the effects of bogie cavities and bogies on the aerodynamic behaviour of a high-speed train (HST) using improved delayed detached eddy simulation (IDDES) at Re ​= ​3.3 ​× ​105. The main aim of this work is to identify the individual influence of bogies and cavities on the surrounding flow, thereby revealing aspects to further improve the HST aerodynamic performance. The accuracy of the numerical method has been validated against the experimental data obtained from a previous reduced-scale moving-model test, a wind tunnel test and a full-scale field test. The underbody flow, wake flow, slipstream velocity, aerodynamic drag and the computational costs are compared for three cases. The results show that installing the bogies around the cavities in Case 1 and sealing the cavities in Case 3 can effectively reduce the turbulence kinetic energy (TKE) and slipstream velocity around the HST. The cavities in Case 2 produce the highest level of TKE and slipstream velocity distribution in both underbody flow region and the wake region, compared to other two cases. This presents the largest scales of the shear vortices in the cavities and longitudinal vortices in the wake. Compared to Case 2, the TSI values of the slipstream velocity at the trackside position decreases by about 18.9% in Case 1 and 56.9% in Case 3, respectively. The cavities account for approximately 65% of the aerodynamic drag of the HST. Installing bogies in Case 1 and sealing cavities in Case 3 gives a 24% and 56% drag reduction for the overall HST. It is recommended to invest 10% higher resources to achieve an accurate surrounding flow prediction of a HST in presence of bogies.

Improved delayed detached-eddy simulation

Aerodynamic performance

High-speed train

Bogie

Cavity

Computational cost

Author

Jiabin Wang

National & Local Joint Engineering Research Center of Safety Technology for Rail Vehicle

Central South University

Guglielmo Minelli

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Tianyun Dong

Central South University

National & Local Joint Engineering Research Center of Safety Technology for Rail Vehicle

Kan He

Chalmers, Mechanics and Maritime Sciences

Sinisa Krajnovic

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Journal of Wind Engineering and Industrial Aerodynamics

0167-6105 (ISSN)

Vol. 207 104406

Subject Categories

Energy Engineering

Vehicle Engineering

Fluid Mechanics and Acoustics

DOI

10.1016/j.jweia.2020.104406

More information

Latest update

11/9/2020