Transient simulation of the aerodynamic response of a double-deck bus in gusty winds

The purpose of the research reported in this paper was to investigate the aerodynamic response of a double-deck bus in gusty winds using a detached-eddy simulation (DES). The bus was subjected to three different scenarios of wind gusts: gust in a wind tunnel, gust in a natural wind, and gust behind the exit of a tunnel. The proposed scenarios of gusts are in the time domain and take into account the dynamic behavior of natural winds. The Reynolds number of the flow, based on the time-averaged speed of the side wind and a reference length of 0.1 m, was 1.3106. Detailed transient responses of the aerodynamic coefficients and flow structures were investigated. Good agreement was found between the DES results and the available experimental data. A comparison between the influence of the different gust scenarios on the aerodynamic coefficients shows that the gust behind the exit from a tunnel has a stronger influence on the aerodynamics than the other gust scenarios. Moreover, the influence of the gusts on the time history of aerodynamic coefficients is found to be limited to the period of the gust