Effect of Variation of Aerodynamic Brake Plate Orientation and Multiple Brake Geometries on Incident Drag of Hyperloop Pod

Abstract

The idea for the Hyperloop has received significant attention, with commentators and analysts expecting it to become a revolutionary and potentially the fastest mode of land transportation on the planet. Various companies and multiple universities are involved in the development of this new system and in combatting the myriad of design challenges that it poses. Of particular interest in academic circles has been the optimization of the pod geometry and fluid flow regime for the functioning of the Hyperloop pod in the low-pressure environment. Multiple studies have been carried out using numerical simulations to obtain insights into the different factors affecting the Hyperloop’s performance. The low-pressure tube through which the Hyperloop pod travels, presents a case that has not been faced in other transport models. The Hyperloop pod is expected to travel at speeds close to Mach 1.0, and as such acceleration and deceleration of the pod is of critical importance if passenger safety protocols are to be maintained. The high-speed flow around the pod exerts high adverse pressure gradients on the pod surface, resulting in boundary layer separation, increasing drag and affecting the acceleration of the pod and requiring greater power. Numerical simulations have shown that the placement of an aerodynamic brake plate on the pod surface at the point at which boundary layer separation occurs in the low-pressure region provides the necessary drag required for safe deceleration, as well as provide the required downforce to counteract the lift forces, which become significant due to the low-pressure regions above the pod, enabling the pod to stay on the track. This study was aimed to find the best angle for the aerodynamic brake plate positioned at a fixed point of 0.24 of the chord length of the pod, allowing for the maximum generation of drag, using numerical simulations. After various trials, it was observed that placing the plate normal to the flow produced the highest drag, with one exception –when angling the plate backwards while increasing its length to keep incident brake profile constant, the drag at first increased slightly and then decreased. This study also studied another design feature, one involving the brake plate split and placed at different chord lengths of the pod.