In this study, numerical simulations were conducted at various pod speeds ($v_{pod}=$ 100–350 m/s) using an unsteady, compressible solver with the Reynolds-averaged Navier–Stokes model to analyze the aerodynamic characteristics and pressure wave behavior in the Hyperloop system. Furthermore, the aerodynamic drag and pressure wave behavior were theoretically predicted based on quasi-one-dimensional assumptions. The flow around the pod is classified into three regimes according to the pod speed based on the compressible flow phenomena. In regime 1 ($v_{pod}=$ 100–170 m/s), the compression waves develop into normal shock waves even without the occurrence of choking at the throat. In regime 2 ($v_{pod}=$ 180–230 m/s), choking occurs at the throat and an oblique shock wave appears within the pod tail section. In regime 3 ($v_{pod}=$240–350 m/s), a trailing shock wave propagates at the end of the oblique shock wave. Due to fully accelerated flow in this regime, the Mach number of the flow behind the pod in a pod-fixed coordinates remains constant as 2.1, regardless of the pod speed. This constant Mach number causes the drag coefficient to decrease while the pod speed increases. Although non-isentropic conditions such as the formation of a boundary layer and flow separation cause variation between the theoretical prediction and simulation results, the predicted properties of the pressure waves and the aerodynamic drag of the pod concur with the simulation results. Because the boundary layer along the pod is thinner at a higher pod speed, the difference between the theoretical and simulation values of the leading shock pressure decreases from 9.71% to 2.83% and that of the leading shock speed decreases from 4.39% to 1.30% as the pod speed increases from 180 to 350 m/s. Additionally, the theoretically predicted drag of the pod shows good agreement with the simulation results with an error of around 6%.

在这项研究中，数值模拟是在各种吊舱速度下进行的（$v_{磷○d}=$100–350 m/s) 使用具有雷诺平均 Navier-Stokes 模型的非定常可压缩求解器来分析 Hyperloop 系统中的空气动力学特性和压力波行为。此外，基于准一维假设从理论上预测了气动阻力和压力波行为。基于可压缩流动现象，根据吊舱速度将吊舱周围的流动分为三种状态。在状态 1 ($v_{磷○d}=$100-170 m/s），压缩波发展为正常的冲击波，即使喉咙不发生窒息。在状态 2 ($v_{磷○d}=$180-230 m/s），喉部发生窒息，吊舱尾部出现斜激波。在制度 3 ($v_{磷○d}=$240–350 m/s)，在斜激波末端传播尾随激波。由于在这种情况下完全加速流动，无论吊舱速度如何，吊舱固定坐标中吊舱后面的流动马赫数保持恒定为 2.1。这个恒定的马赫数导致阻力系数降低，而吊舱速度增加。尽管边界层的形成和流动分离等非等熵条件导致理论预测和模拟结果之间存在差异，但压力波的预测特性和吊舱的气动阻力与模拟结果一致。由于吊舱速度越高，吊舱边界层越薄，超前激波压力的理论值与模拟值之差从9.71%减小到2。当吊舱速度从 180 m/s 增加到 350 m/s 时，83% 和前激波速度从 4.39% 下降到 1.30%。此外，吊舱的理论预测阻力与模拟结果非常吻合，误差约为 6%。