Air-conditioning units (ACUs) are important components of trains, and their performance directly affects the thermal environment of train cabins. Their operational performance is affected by the ventilation capacity of its core component, the cooling fan. The compressible unsteady Reynolds-averaged Navier-Stockes (URANS) and the shear-stress transport (SST) k-ω turbulence model were used to simulate the flow field and pressure waves of high-speed maglev trains, both in open air and tunnels with different lengths, at 600 km/h. We validated the numerical method and settings using a scaled model test. The effects of pressure waves on the fan flow of the ACUs and the flow field around them on the roof of the train were analyzed. The results demonstrated reduced cooling-fan flow due to the high-speed flow generated by the train operation, with the flow of the downstream fan affected by the indoor flow from the upstream fan in the same ACU. The pressure waves from trains passing each other in the open air can cause significant fluctuations in the cooling-fan flow and are positively correlated with the pressure wave amplitude. Moreover, the cooling-fan flow of the ACUs was significantly affected by the tunnel pressure wave, particularly that coming from two trains passing each other in the tunnel. The impact of airflow caused by trains exiting the tunnel on the cooling-fan flow was significantly greater than that entering the tunnel, and the amplitude of the sudden change in the cooling-fan flow was closely related to the gradient of the tunnel pressure wave. Some Findings would help improve the cooling-fan performance and the internal construction design of ACUs.

空调机组（ACU）是列车的重要组成部分，其性能直接影响列车车厢的热环境。它们的运行性能受到其核心部件冷却风扇的通风能力的影响。使用可压缩非定常雷诺平均纳维斯托克斯 (URANS) 和剪应力输运 (SST) k-ω湍流模型来模拟露天和隧道中高速磁悬浮列车的流场和压力波。不同长度，600公里/小时。我们使用比例模型测试验证了数值方法和设置。分析了压力波对列车车顶ACU风扇气流及其周围流场的影响。结果表明，由于列车运行产生的高速气流，冷却风扇流量减少，下游风扇的流量受到同一 ACU 中上游风扇的室内流量的影响。来自露天列车相互经过的压力波会引起冷却风扇流量的显着波动，并且与压力波幅度呈正相关。此外，ACU 的冷却风扇流量受到隧道压力波的显着影响，特别是来自隧道中相互经过的两列火车的压力波。列车出隧道气流对冷却风扇气流的影响明显大于进入隧道的气流，且冷却风扇气流突变幅度与隧道压力波梯度密切相关。一些发现将有助于改善 ACU 的冷却风扇性能和内部结构设计。