Buffer scheme for aero-performance deterioration caused by trains passing bilateral vertical noise barriers with crosswinds

Bilateral vertical noise barriers have been widely used along high-speed railway lines in coastal cities where typhoons are frequent. When a high-speed train (HST) enters (or exits) a noise barrier under strong crosswind conditions, its running safety will be more severely tested because of the instantaneous switching of aerodynamic environment. Installing a buffer structure at the end of the noise barrier is necessary to ensure the running safety of HSTs. In this study, two types of aerodynamic buffer structures (triangle and fence types) for the end of the noise barrier are proposed. The buffering effects of the two structures on the sudden change amplitude of the aerodynamic load of the carriage are compared by using an improved delayed detached eddy simulation method. The difference in the influence of the two buffer structures on the aerodynamic responses of the carriage is discussed by using a wind–train–bridge coupling dynamic response calculation method. The buffer mechanisms of the two structures are revealed in terms of the flow field. Results show that the buffering effect of fence type is superior triangle type, and the buffer length of 4 L is the most reasonable.