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通过大涡模拟(LES)数值计算方法,对均匀定常横风下高速列车的非定常空气动力特性进行了研究。计算得到横风下列车车体所受空气动力的时域及频域特性、列车周围非定常流动结构及相应非定常流场特性。对计算结果分析表明,即使在均匀定常横风下,列车所受空气动力也存在明显的非定常性。对于所研究车型,这种非定常空气动力的特征频率出现在11 Hz以下,并且主要峰值集中在0~3 Hz区间,这与列车系统本身的固有振动模态频率接近,存在横风引起列车系统共振,进而发生列车倾覆的可能;同时研究表明,横风下列车周围流场非定常特性与列车所受非定常空气动力特性在频域中存在对应关系,可以通过测量非定常流场确定列车非定常空气动力特性。
The unsteady aerodynamic characteristics of high-speed trains under a uniform and constant cross-wind are investigated by LES numerical calculation. Calculate the time-domain and frequency-domain characteristics of the aerodynamics of the train body under the cross wind, the unsteady flow around the train and the corresponding unsteady flow field characteristics. The analysis of the calculated results shows that there is obvious unsteady aerodynamics on the train even under a uniform and constant crosswind. For the studied vehicle model, the characteristic frequency of such unsteady aerodynamics appears below 11 Hz and the main peak is concentrated in the range of 0 to 3 Hz, which is close to the inherent vibrational mode frequency of the train system itself. Cross wind causes the train system And the possibility of overturning of the train may occur. At the same time, the study shows that there is a correspondence between the unsteady behavior of the flow field around the train and the unsteady aerodynamics of the train in the frequency domain, which can be determined by measuring the unsteady flow field Constant aerodynamic characteristics.