Assessment of simulation method and grid technology on hyperloop pod aerodynamics in blocked flow

초록

"Hyperloop pods operate at transonic or supersonic speeds in a confined space with significant shock wave system superposition and kurtosis. In addition, the internal flow and temperature fields exhibit complex coupling. This study compares three computational methods, namely, the improved delayed detached eddy simulation based on the shear stress transport (SST) k-ω (M1), unsteady Reynolds averaged Navier-Stokes (URANS) based on the SST k-ω (M2), and URANS based on the realizable k-ϵ (M3) as well as the adaptability of three griding techniques, namely, static, sliding, and overset griding, to investigate their aerodynamic characteristics and the flow field patterns of hyperloop pods. A comparative analysis of the Mach number (Ma), pressure, and temperature distributions in a spatial flow field was performed in a congested flow regime. The flow field parameters between the pod and tube wall were insensitive to variations in the calculation methods. The maximum differences between Ma and the pressure coefficient (Cp) occurred between M1 and M3 at 8.8% and 7.8%, respectively. The response of the tail flow zone to the computational method is very pronounced, with a 22% difference in Ma values in the wake zone between M1 and M3. The differences in Ma and Cp between the static and overset grids are 8.3% and 6.6%, respectively. The results for the sliding and static grids are in agreement. The temperature coefficient responded minimally to changes in the turbulence and grid techniques. This study provides a reference for the selection of computational methods and grid techniques for the aerodynamic characterization of hyperloop pods. © 2025 Author(s).

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