Aerodynamic characteristics of the train under real wind gust

Abstract

Research on aerodynamic loads and flow field characteristics of trains under real wind gust is limited. Most studies focus on train's dynamics under wind gust. By using numerical simulation methods to model the spatiotemporal evolution of the flow field around the train under real wind gust, the aerodynamic load and flow field characteristics of the train were studied. The one-minus-cosine wind gust model was adopted to achieve the real wind gust and the improved delayed detached eddy simulation based on shear stress transport k–ω turbulence model was used to perform numerical simulations of train operation under wind gust by applying the specified wind gust model function to the velocity inlet boundary. During the wind gust, the peak values for most of the aerodynamic loads of the train cannot reach the levels corresponding to those under constant crosswind, since the flow field around the train cannot fully develop into a stable flow field akin to that under constant crosswind. Compared to the wind gust without zero-crossing, the differences between unsteady and quasi-steady peaks are greater for side force, rolling moment, and yaw moment under wind gust with zero-crossing. This study addresses the gap in research on train aerodynamics under real wind gust conditions, providing essential data for train dynamics and a theoretical foundation for the safe operation of the train.