不同风向角下动车组列车穿越深切峡谷桥—隧段气动响应研究OA

The terrain of the tunnel—bridge—tunnel sections in plateau railway canyons is complex,with highly variable strong wind directions.The distribution of aerodynamic loads on trains differs remarkably,posing a direct threat to operational safety.It is thus imperative to conduct research on the influence of wind direction variations on train aerodynamic responses under large canyon terrain conditions.Based on the terrain characteristics of typical plateau railway tunnel—bridge—tunnel canyon sections,a 3D computational model of a full EMU train and employed numerical simulation methods was established to investigate the variation laws of aerodynamic forces,moments,and flow structures during the train's entire passage through the canyon section under different wind directions(30°,60°,90°,120°,150°).The study focused on analyzing the aerodynamic load characteristics of the train at three key positions,i.e.,tunnel exit,mid-span of the bridge and tunnel entrance.The coupling mechanism of canyon terrain and wind directions affecting the train's aerodynamic performance were furtherly revealed.The results demonstrate that the aerodynamic loads on the train vary significantly with wind directions,with the head car exhibiting the strongest response and the mean load reaching its maximum under the 90° wind direction.Under the 60° and 120° wind directions,affected by the flow diversion and local wind speed acceleration in the canyon,the aerodynamic forces on the train generate load peaks that are comparable to those under the 90° wind direction.The coupling effect of complex canyon terrain and incoming wind directions is identified as the primary cause of the differences in train aerodynamic responses.The research findings can provide a scientific basis for wind-resistant design,alignment optimization,and operational safety assessment of high-speed railways in complex terrain.