Aerodynamic Characteristics of a Generic Hyperloop System

Hyperloop is a proposed mode of ground transport that uses depressurised tubes to transport passengers and cargo at high-speeds. The aerodynamic flow regime of a Hyperloop system combines the characteristics of low Reynolds number, high Mach number, and confined/choked flow. This makes it unique compared to more commonly studied aerodynamics problems, and as such it is not yet well understood.

The first section of this project comprises a literature review which aims to evaluate the current state of Hyperloop aerodynamics research. A thorough discussion is presented on the theoretical and numerical methods that have been used to analyse the flow characteristics in model Hyperloop systems.

From here, a rigorous baseline model is constructed by adapting a validated set of simulations for the aerodynamics of a projectile in ground effect. The validation case and baseline model are proposed as representative benchmark cases for numerical simulations of a generic Hyperloop system.

The effects of blockage ratio and Mach number are then considered, as these are the fundamental parameters that determine the flow state of a Hyperloop system. Four primary flow states are observed in the simulations, which is in accord with predictions from 1D theoretical analysis.

Finally, a parametric study of the tube shape is performed, with the objective of reducing the aerodynamic drag on the pod. This highlights that non-circular tube shapes may be preferred, alongside a need to maximise the symmetry of the configuration where possible.

Overall, a number of insights into the expected aerodynamics of Hyperloop systems are found, which will hopefully pave the way for future research efforts in this unique application.