This study numerically investigates the effects of Jacobs bogies on the aerodynamic behaviors of a high-speed train using improved delayed detached eddy simulation (IDDES) at Re ​= ​3.3 ​× ​105. The results of the numerical simulations have been validated against the experimental data obtained from a previous reduced-scale moving model test and a wind tunnel test. The slipstream velocity, wake flow, underbody flow and aerodynamic drag of the HST are compared between the conventional bogie case and Jacobs bogie case. The results show that the use of Jacobs bogies can reduce the TSI values of the slipstream velocity at trackside and platform positions by 11.07% and 22.40%, respectively, which thereby shows a positive effect on improving the safety level of trackside workers and passengers standing on the platform. The Jacobs bogies are found to decrease the maximum values of the slipstream velocity and turbulence kinetic energy occurring at the intermediate bogie regions beneath the HST by 30.08% and 41.32%, respectively, which is beneficial for weakening the ballast flight phenomenon. The Jacobs bogies significantly narrow the scale of the longitudinal vortex structure in the wake propagation region. Additionally, the application of Jacobs bogies lowers the aerodynamic drag values of the vehicles and contributes to a 10% total drag reduction.

中文翻译：

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雅各布转向架对高速列车滑流和尾流影响的 IDDES 研究

本研究使用改进的延迟分离涡流模拟 (IDDES) 在 Re = 3.3 × 105 下数值研究 Jacobs 转向架对高速列车空气动力学行为的影响。数值模拟的结果已经根据从先前缩小比例的移动模型测试和风洞测试中获得的实验数据进行了验证。比较了传统转向架和 Jacobs 转向架之间 HST 的滑流速度、尾流、底部流和气动阻力。结果表明，采用 Jacobs 转向架可使轨旁和站台位置的滑流速度 TSI 值分别降低 11.07% 和 22.40%，从而对提高站旁站台工人和乘客的安全水平起到积极作用。该平台。发现Jacobs转向架使HST下方中间转向架区域出现的滑流速度和湍流动能的最大值分别降低了30.08%和41.32%，有利于减弱压载飞行现象。Jacobs转向架显着缩小了尾流传播区域中纵向涡结构的尺度。此外，Jacobs 转向架的应用降低了车辆的气动阻力值，并有助于减少 10% 的总阻力。Jacobs转向架显着缩小了尾流传播区域中纵向涡结构的尺度。此外，Jacobs 转向架的应用降低了车辆的气动阻力值，并有助于减少 10% 的总阻力。Jacobs转向架显着缩小了尾流传播区域中纵向涡结构的尺度。此外，Jacobs 转向架的应用降低了车辆的气动阻力值，并有助于减少 10% 的总阻力。