蒋欣, 杜俊涛, 尚克明. 尾部吹气控制对城轨列车气动阻力的影响[J]. 空气动力学学报, 2023, 41(7): 120−129. doi: 10.7638/kqdlxxb-2022.0113
引用本文: 蒋欣, 杜俊涛, 尚克明. 尾部吹气控制对城轨列车气动阻力的影响[J]. 空气动力学学报, 2023, 41(7): 120−129. doi: 10.7638/kqdlxxb-2022.0113
JIANG X, DU J T, SHANG K M. Influence of tail-blowing control on aerodynamic drag of urban rail trains[J]. Acta Aerodynamica Sinica, 2023, 41(7): 120−129. doi: 10.7638/kqdlxxb-2022.0113
Citation: JIANG X, DU J T, SHANG K M. Influence of tail-blowing control on aerodynamic drag of urban rail trains[J]. Acta Aerodynamica Sinica, 2023, 41(7): 120−129. doi: 10.7638/kqdlxxb-2022.0113

尾部吹气控制对城轨列车气动阻力的影响

Influence of tail-blowing control on aerodynamic drag of urban rail trains

  • 摘要: 为了探索尾部吹气控制对城市轨道交通列车气动阻力的影响,采用基于Realizable k-ε两方程模型的DDES方法模拟列车明线运行时的车身周围流场结构,分析了在尾车不同位置施加吹气控制,以及不同吹气速度的影响规律,并通过风洞试验结果验证了文章选用的数值模拟方法。研究结果表明:压差阻力是列车阻力的重要来源,约占总阻力的80.1%,摩擦阻力占比约为19.9%;列车尾车设置吹气控制可显著减小列车气动阻力,且对列车压差阻力的影响远大于摩擦阻力;不同吹气方案下,尾车减阻效果最显著,其次是中间车,最高减阻率分别为27.6%和 4.6%;分离点区域压力和流向涡强度是影响列车阻力的重要因素,吹气边界靠近流向涡涡核时可弱化流向涡强度,特定吹气边界控制下列车尾车压差阻力的减阻率高达31.9%;列车气动减阻率随吹气速度增大而增大,当吹气速度由0.2U增大至0.4U时,整车气动减阻率由7.9%增大至12.2%,继续增大至0.6U气动减阻效果减弱,整车减阻率增大至12.9%;集中吹气点通过改变吹气方向与壁面切线方向的夹角来控制尾流结构,当集中吹气点从距尾车鼻尖点1.5 m增大至5.0 m时,列车气动减阻率由12.9%减小至11.3%。

     

    Abstract: In order to explore the influence of tail-blowing control on the aerodynamic resistance of urban rail trains, the DDES method based on realizable k-ε two-equation model is used to simulate the flow structures around the train body on open railways, and the numerical method is verified by wind tunnel test results. The influence of the tail-blowing control at different positions and different blowing speeds is analyzed. The results show that, the pressure drag is an important source of the train resistance, accounting for about 80.1% of the total resistance, while the friction drag accounts for about 19.9%. The air blowing control can significantly reduce the aerodynamic resistance of the train, with much greater influence on the pressure drag than the friction drag. Under different air blowing schemes, the drag reduction effect on the rear car is most significant, followed by the middle car, with the highest drag reduction rates of 27.6% and 4.6%, respectively. The pressure in the separation area and the strength of the streamwise vorticity are important factors affecting the train resistance. When the blowing boundary is close to the core of the streamwise vortex, the streamwise vorticity is weakened. When the blowing speed increases from 0.2U to 0.4U, the drag reduction rate increases from 7.9% to 12.2%. When the blowing speed further increases to 0.6U, the drag reduction effect weakens, with the overall drag reduction rate reaching 12.9%. The wake structure varies with the angle between the blowing direction and the wall tangential direction. When the central blowing point increases from 1.5 m to 5.0 m from the nose tip of the tail car, the aerodynamic drag reduction rate of the train decreases from 12.9% to 11.3%.

     

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