【摘要】 采用基于SST k-ω的IDDES湍流模型研究轨道车辆冰雪风洞流道空气流动品质，并分析收缩段约束曲线对试验段内流场品质的影响。采用风洞流场校测的数据验证本文数值模拟方法的计算精度可靠性、网格尺度无关性和湍流模型适应性。研究结果表明：原始工况下，收缩段入口处由于拐角导流片导致流动分离，气流速度呈锯齿状分布；在试验段喷口前未发生明显流动分离，试验段速度均匀分布；喷口射流与周围的动量交换而导致速度较低，涡量增加，湍流度也较高。不同收缩段曲线工况中，维氏曲线在收缩段入口位置过快收缩，导致截面的速度均匀性较差，维氏曲线对一阶变量如速度、俯仰角、偏航角等变量影响较大，双三次曲线对二阶变量影响较大。综合考虑风洞收缩段气动外形关键参数设置，五次收缩段曲线对保证试验段流场品质效果最佳。更多还原

【Abstract】 The IDDES turbulence model based on SST k-ω was used to study the air flow quality in the passage of the ice and snow wind tunnel for rail vehicles, and the influence of the constraction curve on the flow field quality in the test section was analyzed. The reliability of calculation accuracy, grid independence validation and turbulence model adaptability of the numerical method in this paper were verified by the wind tunnel flow field calibration data. The results show that in the original case, due to the flow separation at the inlet of the contraction section behind the corner deflector, the airflow velocity is in zigzag distribution; no obvious flow separation occurs before the nozzle of the test section, and the area where the velocity in the test section is uniformly distributed. The momentum exchange between the nozzle jet and its surroundings leads to low velocity, and increases vorticity and high turbulence intensity. In different cases of contraction section curves, the witozinsky curve shrinks too fast at the entrance of the contraction section, resulting in poor velocity uniformity of this section. The witozinsky curve has a greater impact on the first order variables such as velocity, pitch angle, yaw angle, etc., and the bicubic curve has a greater impact on the second order variables. Therefore, the quintic curve is more effective to ensure the flow field quality by comprehensivelyconsidering the key parameters setting strategy of the aerodynamic profile of the wind tunnel contraction section.更多还原