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Severe weather, especially strong rain-loaded wind, appears in coastal areas frequently. The strong wind driving raindrops worsens the wind effect and aggravates its impact on the intercity railway bridge and running trains. Based on the Euler multiphase model, for evaluating the effect of raindrops in wind and rain environment on running trains, a numerical simulation approach was adopted in this study, and the influence of the crosswind speed and rainfall with varying characteristic parameters on the aerodynamic performances of intercity trains was analysed. The results showed that the airflow around the train drove some raindrops to show a parabolic projectile feature, and the projectile distance increased as the crosswind speed increased, but the projectile distance showed no noticeable change with the rise in the rainfall, because the impact of the crosswind played a dominant role, while the raindrops provided additional effects in the wind and rain environment. Furthermore, in the wind and rain environment, as the crosswind speed increased and compared to that of the 10 m/s conditions, an increase of 354.37 %, 369.60 % and 355.07 % in CS, CL and CM of the whole train was shown in 30 m/s wind speed conditions, respectively, while, as the rainfall increased to 100 mm/h compared to that of the 20 mm/h, an increase of 6.41 % and 6.25 % in CS and CM of the whole train, as well as a decrease of 0.71 % in CL of the whole train was shown, respectively.

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.