Drag-based aerodynamic braking system for the Hyperloop: a numerical study

2020 ◽  
pp. 1-10
Author(s):  
Mohammed Raihan Uddin ◽  
Tahsin Sejat Saniat ◽  
Sayedus Salehin ◽  
Md. Hamidur Rahman
Keyword(s):  
High Speed ◽  
Aerodynamic Drag ◽  
Numerical Study ◽  
Detailed Comparison ◽  
Sustainable Transportation ◽  
Transport Infrastructure ◽  
Braking System ◽  
Passenger Safety ◽  
Aerodynamic Brake ◽  
High Mach

The Hyperloop promises to revolutionize the transport infrastructure of the 21st century by reducing travel time and allowing people to reach transonic speed on land. It carries with it the hope of a sustainable transportation system during an era of global energy crisis. Overall passenger safety in a high-speed pod necessitates a reliable braking system. This paper introduces the possibility of utilizing aerodynamic drag in the Hyperloop, anticipated to operate at high Mach and low Reynolds flow regime, to attenuate the speed of the pod. Numerical analysis was conducted to investigate the effect of incorporating an aerodynamic brake at different pod velocities (100, 135, and 150 m/s) and deployment angles (30°, 45°, 60°, and 90°). A detailed comparison between the proposed aerodynamic braking system (AeBS) and existing braking systems for the Hyperloop has been presented in this paper. The results demonstrate an increase in drag value of the pod by 3.4 times using a single 0.15 m2 brake plate. When the brake plate was fully deployed at a pod velocity in excess of 112 m/s, the aerodynamic drag-based braking systems was shown to be more effective than the contemporary eddy current braking system.

EXPERIMENTAL AND NUMERICAL STUDY OF THERMAL ANALYSIS OF HIGH-SPEED FRICTION BRAKING SYSTEM

2011 ◽  
Vol 10 (01) ◽  
pp. 135-142
Author(s):  
CHUNMEI ZHANG ◽  
YONGFENG LI
Keyword(s):  
Thermal Analysis ◽  
Friction Surface ◽  
High Speed ◽  
Material Selection ◽  
Numerical Study ◽  
Friction Pair ◽  
Maximum Temperature ◽  
Dimensionless Time ◽  
Braking System ◽  
Friction Braking System

Thermal analysis can be used as one of the basis for the friction pair material selection in high-speed friction braking system. In this study, the experimental results showed that surface temperature could be reduced by increasing the radius of the friction disk or thermal conductivity coefficient of disk material with stable braking; In the early stage of long braking, the temperature on the friction surface rises rapidly, but further braking does not lead to a significant rise in temperature; In the case of short braking, there is not enough time for the friction surface to reach the critical temperature, and the disk surface reaches the maximum temperature at the end of braking. During long braking, the dimensionless time capacity of the friction surface reaching the highest temperature is F0 ≈ 0.1F0s.

Study of Incident Drag Response of Hyperloop Pod Based on Change in Aerodynamic Brake Plate Orientation

2021 ◽  
Author(s):  
Shadman Mahmud ◽  
Adib Adnan ◽  
Shahnoor Shamim Khan ◽  
Md. Hamidur Rahman
Keyword(s):  
Boundary Layer ◽  
Numerical Simulations ◽  
High Speed ◽  
Boundary Layer Separation ◽  
Pressure Gradients ◽  
Transport Models ◽  
Layer Separation ◽  
Passenger Safety ◽  
Speed Flow ◽  
Aerodynamic Brake

The idea for the Hyperloop has received significant attention, with expectations of it becoming a revolutionary and potentially the fastest mode of land transportation on the planet. The low-pressure tube through which the pod travels at expected speeds close to Mach 1.0, presents a unique case among other transport models, and as such, braking 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. 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 provides the necessary drag required for safe deceleration. This study was aimed to find the best angle for the aerodynamic brake positioned at a fixed point on the pod, allowing for the maximum generation of drag, using numerical simulations. After various trials, it was observed that angling the brake 15° backwards while increasing its length to keep incident brake profile constant, the drag value obtained was the highest.

scholarly journals DRAG ANALYSIS OF AERODYNAMIC BRAKING SYSTEM FOR THE HYPERLOOP POD

2021 ◽  
pp. 78-86
Author(s):  
Syed Habeeb ◽  
Kavati Aakaanksha ◽  
Abdul Rahman ◽  
Ms. D Anitha ◽  
Dr. D Govardhan
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Flow Simulation ◽  
Braking System ◽  
Ansys Cfx ◽  
Left And Right ◽  
Braking Force ◽  
Aerodynamic Brake ◽  
Drag Analysis

This research presents the results of the aerodynamic brake plates mounted on the hyperloop pod, on a fluid flow field, and overall braking force under the same velocity with different angle deployment of the brake plates. Aerodynamic brake plates are designed to generate the braking force by increasing the aerodynamic drag when It was deployed against the fluid flow, in this research three plates are used one is a horizontal plate mounted on the roof of the pod and the remaining two are vertical plates which are mounted on the left and right side of the hyperloop pod. In this research to develop the case studies different combinations of angle deployment of the brake plates are used, the sixteen cases of hyperloop pods with different angle deployment of brake plates are designed by using CATIA VR-6R. the flow simulation was made by Ansys CFX software for sixteen cases of the pods with different angle deployment of the brake plates under the same velocity. This research founds that the aerodynamic drag force is a function of angle deployment of the brake plates under the same velocity, drag force can increase or decrease by changing the angles of the brake plates. the result shows that 2.4 times of drag force increased for a fully deployed angle of attack of the brake plates when compared with the the same pod with no brake plates shows us that employing the brake plate increases the drag force This outcome will provide a major contribution to the development of the aerodynamic braking system of the hyperloop pod. KEYWORDS: hyperloop pod, aerodynamic drag, 𝑘 − 𝜔 model, aerodynamic brake

Aerodynamic behavior of a high-speed train with a braking plate mounted in the region of inter-car gap or uniform-car body: A comparative numerical study

2020 ◽  
pp. 095440972096582
Author(s):  
Jiqiang Niu ◽  
Yueming Wang ◽  
Feng Liu ◽  
Rui Li
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Numerical Study ◽  
Aerodynamic Performance ◽  
Body Region ◽  
High Speed Train ◽  
Detached Eddy Simulation ◽  
Continuous Increase ◽  
Car Body

The continuous increase in train speed has brought serious challenges to train braking safety. Aerodynamic braking technology can effectively improve the braking effect of trains at high speeds. In this study, an aerodynamic braking device installed in the inter-car gap region (ICG) of a high-speed train is proposed and the aerodynamic performance of the high-speed train with an aerodynamic braking device is assessed by improved delayed detached eddy simulation (IDDES) based on the κ-ω turbulence model. The results show that the opening of the plate significantly changes the aerodynamic performance of the train, thereby greatly increasing the aerodynamic forces of the train and their fluctuation degree. The effect of the opening of the plate increases the turbulence of the downstream flow field around the tail car. The affected area is mainly concentrated in the flow field around the location of the plate for the pressure field and the whole flow field behind the plate for the velocity field. The effect of the plate mounted on the uniform-car body region (UCG) on increasing the aerodynamic drag is better than that at the ICG, though the aerodynamic fluctuation and the influence on the surrounding flow field will also be great.

Light Railways as the Basic for Transport Infrastructure Development in Northern Territories of Russia

2020 ◽  
pp. 97-101
Author(s):  
P.I. Tarasov
Keyword(s):  
High Speed ◽  
Road Transport ◽  
Transport Infrastructure ◽  
The Arctic ◽  
Infrastructure Development ◽  
Capital Costs ◽  
New Type ◽  
The Republic ◽  
Northern Territories ◽  
Mode Of Transport

Research objective: studies of economic and transport infrastructure development in the Arctic and Northern Territories of Russia. Research methodology: analysis of transport infrastructure in the Republic of Sakha (Yakutia) and the types of railways used in Russia. Results: economic development of any region is proportional to the development of the road transport infrastructure and logistics. When a conventional railway is operated in the Arctic conditions, it is not always possible to maintain a cargo turnover that would ensure its efficient use, and transshipment from one mode of transport to another is very problematic. A new type of railway is proposed, i.e. a light railway. Conclusions: the proposed new type of transport offers all the main advantages of narrow gauge railroads (high speed of construction, efficiency, etc.) and helps to eliminate their main disadvantage, i.e. the need for transloading when moving from a narrow gauge to the conventional one with the width of 1520 mm, along with a significant reduction in capital costs.

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

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