Abstract
You might have heard the term ‘Hyperloop’ somewhere. In recent times, this term has created quite a hype by capturing people’s imagination as the potential fifth mode of transportation. Elon Musk coined the term ‘Hyperloop’ and it was first introduced in his blog named ‘Hyperloop Alpha’ presented in 2013. Hyperloop was projected as a super-fast land transportation system. Over the years, many technical advancements and design changes have been made to the project and it is expected that the first hyperloop network will be completed by 2030.
Keywords
Hyperloop, Levitating, Propulsion, Aerodynamics, Air Drag, Linear Induction Motor, Magnetic Levitation, Polar Repulsion.
Introduction
The term Hyperloop is used to denote the concept of a new form of high-speed land transportation system wherein both passengers and freight will be able to travel at supersonic speeds. This concept is based on the Vactrain concept which was first invented by Robert H. Goddard in 1904. Goddard subsequently refined the idea and it was finally summarized and published in a Scientific American editorial in 1909 called "The Limit of Rapid Transit". Elon Musk introduced the initial designs that were based on the idea of using low-pressure or vacuum tubes through which levitating pods may travel substantially free of air resistance or friction. Thus, being able to achieve speeds over 700 mph. But this design was set aside due to some safety issues. Subsequently, the idea of magnetic levitation was applied to the Hyperloop program which was found to be more practical and cost-effective.
Initial Designs
The initial design as proposed by Elon Musk in a blog paper labeled ‘Hyperloop Alpha’ was based on the concept of air pressurization and aerodynamic lift. The Hyperloop consists of various components- Capsule, Tube, and Propulsion.
Capsule
It is a streamlined shape object slightly raised from the front to optimize capsule speed and performance. The streamlined shape was used to reduce drag force. The vehicle features a propulsion system at the front to ingest oncoming air for levitation and propulsion to a lesser extent. The interiors of the capsule focused on passenger safety and comfort by making seats that conform to the body of the passenger to maintain comfort during high-speed accelerations. The doors will have a sliding mechanism or lateral opening for easy access during trips. Below the capsule, there will be air bearings or skis as suspension mechanisms. Here the concept of aerodynamic lift comes into play as the use of air bearing mechanism offers the high stiffness required to maintain stability at high speeds. During rest, the air bearings will slowly lower the capsule to the ground and on starting movement they will raise the capsule enabling it for air levitation. In addition to them, the addition of deployable wheels was also proposed to be used under 100 mph as part of the additional safety system. Another important feature of the capsule is the onboard compressor which serves two purposes. The system supplies air to air bearings that support the weight of the capsule throughout the journey. It also allows the pod to traverse narrow tubes as well, by preventing the choking up of air between the tube and capsule. A fan is attached to the front nose of the pod whereby incoming air enters and goes into the compressor. A storage container is attached to the compressor where compressed air is stored for further usage. The diagrammatic representation of this Capsule is given below.
Tubes
They are an interconnected network of closed steel tubes used for transporting the capsules. Two types of tubes can be summarised- Underground tubes and Tubes on Pillars. Out of them, the latter has been considered more appropriate due to safety concerns. The tubes will be circular and will be made of sections, with every section welded to each other and then bolted together for structural integrity. There will be Solar Panels on the top of tubes for providing the uninterrupted energy supply needed to keep the system running. Apart from this, two tubes will be placed side-by-side for ease of usage and decongestion purposes. The diameter of the tubes will be optimized according to the size of the capsule for smooth airflow around the capsule. The stations will be transit areas with two airlocks signifying the arrival and departure of the Hyperloop. The diagrammatic representation of the cross-section of the tube is given below.
Propulsion System
The Propulsion system is mainly used for accelerating and deaccelerating the capsule in the tube. It consists of various components positioned both on the capsule and along the tube. A linear induction motor is used to accelerate or deaccelerate the capsule. Rotors are attached to the capsules aligned with the stators placed in the tube at uniform distances to make a capsule control system and electromagnetic centering.
Working
The Linear Induction Motor will provide initial velocity to the capsule levitating in the air with the use of air bearings or skis and will help the capsule enter the tube with low air pressure. Thus, reducing the drag force and significantly increasing travel speeds. The Linear Induction Motor will provide a boost to the already moving capsule. Though the linear motors will be powered by the energy stored by the solar panels, in case of any failures additional battery backups are also located along the track for smooth functioning of the system as a whole unit.
Problems
The initial design though considered essential for popularising the concept of Hyperloop was set aside due to a few concerns. One of the main concerns was the sophistication of the air bearing mechanism and the presence of air pressure though in low quantities but still providing air drag and limiting the speed of the capsule. Another concern was related to the design flaws in the capsule as it was pointed out by many that the design needed to be more aerodynamic and the distance between the pod and the tube needs to be increased for smooth air transmission. Another concern related to infrastructural requirements was the high cost of building and maintaining such a sophisticated system. Thus, due to these reasons, this design was removed and better alternatives were developed.
Modern Design
The improved design is based on the principle of magnetic levitation and polar repulsion. It ends the need for the air-bearing mechanism and the propulsion system attached at the front to supply air to the skis. The tube is laid out with electromagnets throughout the network and they are also attached to the bottom of the capsule. Thus, establishing a system of polar repulsion and achieving levitation. Apart from this, the tubes are also made vacuum to completely end the air drag and make the system seamless.
Capsule
The capsule's design is made more aerodynamic efficient. The propulsion system at the front has also been removed as the air-bearing mechanism is replaced with magnetic levitation. Thus, reducing the weight of the pod and providing additional space for passengers. Apart from this, the initial design has been kept intact with the front end slightly raised, the seating pattern remaining the same and the battery pack still placed at the end for weight management.
Tube
The design of the tube network has been more or less kept the same. Only one change has been made to the tubes that they are made vacuum rather than low pressured for ending air drag.
Propulsion
The propulsion system has remained unchanged with the use of a linear induction motor system still in place for accelerating and deaccelerating the pod.
Current Status of Development
The original concept introduced by Elon Musk was not copyrighted and kept open-sourced so that inventors and companies around the world could develop their individual Hyperloop Systems simultaneously. Thus, boosting the speed of development of the concept. Numerous companies are involved in the development of the Hyperloop System with each one using different technologies. The major players in the race for development are Virgin Hyperloop, Hyperloop Transportation Technologies (HTT), Trans-pod, and Hardt Global Mobility. Among them, Virgin Hyperloop created history on 8 November 2021 by completing the first human test ride successfully. Virgin Hyperloop is also in talks with governments around the world to create Hyperloop networks in their countries. Some of the countries that have made agreements with Virgin Hyperloop are the USA, India, and Saudi Arabia. In India, there are plans to create a Mumbai-Pune Hyperloop Network initially which will be later on expanded to other countries as well.
Conclusion
The Hyperloop program is still in the development and testing stage. The initial development in the concept looks promising and further opens up various avenues of research and development related to the Mars Transportation System and Electric Planes concepts. It is expected that the first Hyperloop System will be completely functional and open for public usage by 2030. The Hyperloop Program also provides an eco-friendlier and more sustainable substitute to the conventional modes of transportation. Thus, solving major environmental concerns related to pollution and the environment’s degradation. Overall, the Hyperloop concept if developed successfully will mark a new phase in the human transportation systems.
References
Musk, Elon (12 August 2013) “Hyperloop Alpha” Blog, www.tesla.com
Steve Ranger (16 August 2019) “What is Hyperloop? Everything you need to know about the race for super-fast travel” www.zdnet.com
Cassandra (16 November 2020) “How does Hyperloop work? Everything you need to know about Magnetic Levitation” www.alphr.com
Pegasus Project, www.virginhyperloop.com
Very good explanation 💯💯💯🙌🙌