Aerodynamic characteristics of double-connected train groups composed of different kinds of high-speed trains under crosswinds: A comparison study

As train speeds continuously increase, the crosswind stability of high-speed trains (HSTs) has been a prominent research topic. Benefiting from advances in railway technology, the coupled operation of different HSTs has been proven to be permissible, but the crosswind performance of double-connected train groups composed of different kinds of HSTs has rarely been studied. This paper therefore studied the differences in the aerodynamic performance of double-connected train groups composed of same and different train units under crosswinds. We employed an improved delayed detached-eddy simulation (IDDES) method to investigate the flow features around different groups of double-connected train. Two one-eighth-scale standard HSTs-Train 1 (T 1) and Train 2 (T 2)-currently operating in China were selected to form different group configurations for double-connected trains: T 1-T 1 (Case 1-1), T 1-T 2 (Case 1-2), T 2-T 1 (Case 2-1), and T 2-T 2 (Case 2-2). First, the reliability of the numerical algorithm and mesh independence were verified to ensure the accuracy of the numerical results. Second, the aerodynamic force coefficients, time-averaged, and instantaneous flow structures of different double-connected train group types were compared and analyzed.(c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).