Mitigating the Piston Effect in High-Speed Hyperloop Transportation: A Study on the Use of Aerofoils

Abstract

The Hyperloop is a concept for the high-speed ground transportation of passengers traveling in pods at transonic speeds in a partially evacuated tube. It consists of a low-pressure tube with capsules traveling at both low and high speeds throughout the length of the tube. When a high-speed system travels through a low-pressure tube with a constrained diameter such as in the case of the Hyperloop, it becomes an aerodynamically challenging problem. Airflow tends to get choked at the constrained areas around the pod, creating a high-pressure region at the front of the pod, a phenomenon referred to as the “piston effect.” Papers exploring potential solutions for the piston effect are scarce. In this study, using the Reynolds-Average Navier–Stokes (RANS) technique for three-dimensional computational analysis, the aerodynamic performance of a Hyperloop pod inside a vacuum tube is studied. Further, aerofoil-shaped fins are added to the aeroshell as a potential way to mitigate the piston effect. The results show that the addition of fins helps in reducing the drag and eddy currents while providing a positive lift to the pod. Further, these fins are found to be effective in reducing the pressure build-up at the front of the pod.

Demand for Passenger Capsules for Hyperloop High-Speed Transportation System—Case Study From Poland

“…It is a system that could conduct all functions. You can read about the research on the aerodynamic properties of the HP capsule inside the vacuum tube in this article [13], while about the technical aspects of the cooperation of magnetic elements with the guide placed in the tube in this article [4]. Some capsule design methodologies have received an award for innovation in design concept [14].…”

“…After the capsules are ready for the further journey, the door ( 10) is opened and the next passengers board (11). After boarding is complete, the door is closed (12) and the module moves toward the free lock (13). In the lock, the module waits for the pressure to change and is handed over to the crane (14) for handling.…”

Numerical Study of Longitudinal Inter-Distance and Operational Characteristics for High-Speed Capsular Train Systems

“…Capsular vehicles have a lot of advantages over traditional on-ground transportations like high speed, capacity, fuel efficiency, operational cost, environmentally friendly, etc., [17][18][19]. Among various subject areas for realization including communication [20,21], software systems and their designs [22], performance modeling and simulations [23], energy management [24]and eco-friendly effect [25], train control management and operation [26][27][28], this paper focuses on the inter-distance control aspect in operation since its inter-distance is directly related to the number of passengers, freight, and the overall efficacy of hyperloop system operation. M. Overton et al focused on and described the capsule hazards and mitigations along with specialized evacuation processes appropriate for Hyperloop [29].…”

“…[17][18][19]. Among various subject areas for realization including communication [20,21], software systems and their designs [22], performance modeling and simulations [23], energy management [24] and eco-friendly effect [25], train control management and operation [26][27][28], this paper focuses on the inter-distance control aspect in operation since its inter-distance is directly related to the number of passengers, freight, and the overall efficacy of hyperloop system operation.…”

Design and optimization of nine degrees of freedom suspension model for hyperloop pods

“…This change in the levitation height increases the drag forces because of the Kantrowitz limit. [3][4][5] In this regard, Hyperloop pioneers worldwide are exploring various suspension systems and aerodynamic bearing systems. Electromagnetic suspension system (EMS) and Electrodynamic suspension system (EDS) are two of such systems, which are ascertained as suitable for Hyperloop design.…”