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.