Hyperloop Makers UPV

Hyperloop UPV (a.k.a. Hyperloop Makers UPV) is a team of students from the Universitat Politècnica de València (Valencia, Spain) designing a rail-free concept of Hyperloop. They were awarded Top Design Concept and Propulsion/Compression Subsystem Technical Excellence Award^[1] at SpaceX's Design Weekend, the first phase of the Hyperloop Pod Competition held in Texas on January 2016.

Their design stands out for its use of magnetic levitation based on attraction to the top of the tube thanks to their unique levitation units located at the top of the pod, instead of air-bearing systems based on repulsion to a rail located at the bottom of the tube. Their clean tube layout allows for compensation of inertial forces allowing higher curve radius, reduced air-evacuation cost and up to 30% savings in infrastructure. Powered by detachable batteries, propulsion is obtained through compression and expansion of the air with a nozzle. A turbine recovers energy from the flow allowing a more efficient journey.

The initial team in Design Weekend was composed of five students from the student community Makers UPV: Ángel Benedicto, Daniel Orient, David Pistoni, Germán Torres and Juan Vicén, together with advisor Vicente Dolz, assistant Professor at CMT- Motores Térmicos,^[2] Universitat Politècnica de València.

The team was expanded to more than 30 students in September 2016 in order to build a full-size prototype for SpaceX's Pod Competition,^[3] and in April 2017 the team was selected by SpaceX to participate in the Hyperloop Pod Competition 2, which wil be held in Los Angeles days 25–27 August 2017 in collaboration with Purdue University[4][4], becoming the world's first transatlantic student collaboration in the history of the development of the Hyperloop.

History

The Hyperloop Makers UPV team was created in August 2015 when Daniel Orient, aerospace engineering student, read in a piece of news that with Hyperloop, airplanes would be useless for medium-range journeys (about 600 km). When he discovered that Elon Musk was organising a contest to make Hyperloop a reality and that it was open-source, he decided to ask for help to Makers UPV, a local community of makers from Valencia, Spain. That's when Ángel Benedicto, David Pistoni, Germán Torres and Juan Vicén decided to take part on the project and build together their own Hyperloop concept.

The team was selected to take part on the contest by SpaceX on November 2015 among other 700 applicants from world's top universities, as stated on Business Insider.^[5]

By December 2015 the team finally obtained their first license by ANSYS simulation software provider and they started running simulations, which they used to write the "Hyperloop Makers UPV Technical Report", published on January 2016.^[6]

The document is a scientific report aimed at convincing the community of their new Hyperloop system, which could improve transportation, both of passengers and cargo.

The team decided to make the document public at their website to boost the development of Hyperloop.

The Polytechnic University of Valencia supported the team to travel to Texas, where they obtained Top Design Concept Award and Propulsion/Compression Subsystem Technical Excellence Award.^[7]

After the event, the team gained international attention worldwide because they were the smallest team and they obtained the highest "awards-to-team size" ratio, with 2 awards for a team of 5 students plus their university advisor.^{[8][9][10][11]}

They also appeared on Spanish TV (TVE, Antena 3),^[12][13] radio shows (RNE) ^[14][15][16] and institutional organisations such as Marca España.^[17]

Then, the team decided to launch a fundraising campaign to obtain the resources to make their project a reality, holding a series of talks around Spain.^[18]

On March 2016 Jesiva Transformers, a company focused on coils and transformers located in Vilamarxant (Valencia, Spain), announced their support to the team.

On 16 April 2016 the team participated in a TEDx event organized by Berklee College of Music in Valencia, with their talk "Hyperloop: from Valencia to the world".^[19]

On 19 April 2016 the team performed a talk in City of Arts and Sciences, one of the most important Spanish buildings, where they stated that the journey Valencia - Paris could be reduced to 1 hour 20 minutes with their Hyperloop concept.^[20]

On 11 July 2016 the team reached a collaboration agreement with ISTOBAL, a Spanish leader in the design, manufacture and marketing of carwash solutions for the automotive sector.^[21][22][23]

On 22 July 2016 the team reached a collaboration "Premium Partner" agreement with NAGARES S.A,^[24] a Spanish company focused on research, development, manufacturing and sales of electronic systems mainly for the automotive sector.^[25][26]

The team keeps working and is determined to bring to the Competition Weekend a demonstrator of their technology by January 2017.

On September 2016, the team was expanded to more than 30 students in order to build a full-size prototype for SpaceX's Pod Competition^[3] for Summer 2017.

Technology

The Hyperloop UPV concept^[6] is a levitating rail-free pod design. Using magnetic repulsion and air cushioning for levitation is expensive and can produce unpredictable forces. The pod is equipped with a hybrid system of permanent magnets and electromagnet units, being able to control lift, so it can hover from the top of the tube. That way, the pod doesn't need so much electricity to be lifted by itself. Propulsion is obtained through expansion of the air with a nozzle, located at the rear of the pod, achieving speeds of up to 1000 km/h. The turbine recovers energy from the flow allowing a more efficient journey. This clean tube layout is said to cut costs in up to 30% of the whole Hyperloop project (about 180m USD) and the possibility to comfortably fit more passengers.^[27]

Levitation System

The Hyperloop UPV team has designed a new magnetic levitation system for the future of transportation.

There are two main levitation methods:

1. Electromagnets: they need electrical power, like batteries, to work. But lifting the whole pod would require a lot of batteries.
2. Permanent magnets: they can lift big loads without electricity consumption, but mass variations in the pod could make the system unstable, sticking the pod to the top of the tube.

The Hyperloop UPV team combines both levitation methods:

Permanent magnets produce the main lift force and electromagnets control the gap distance to the tube.

This way low energy consumption plus an accurate force control can be obtained.

If levitation units are located on top of the pod in radial configuration, an accurate control of the gap size can be achieved, obtaining a fully autonomous levitation system.

This rail-free levitation system has the following advantages:

1. Compensation of inertial forces: allowing a higher curve radius of the track.
2. Better tube sealing: reduction of leakages.
3. Savings in tube construction: no rails nor concrete inside the tube, a clean tube layout.
4. Enhanced scalability: possibility to increase the size for freight transportation and achieving supersonic speeds once solved the transonic limits.

The levitation system has been validated with a real model of a magnetic levitator from the Institute of Automatic Systems (ISA)^[28] available at the University. Firstly, the levitation system consistent in electromagnet-magnet has been validated to be controlled in a stable behavior and after that the proposal design has been simulated with the ANSYS Maxwell software.

In addition, dynamic behavior has been studied in order to obtain the influence of Lenz's Law. The result of the studies show that Lenz's Law reduces the effectiveness of the levitation system up to 75% at 260 m/s.

This fact could be overcome by reducing the gap thickness between the tube and the pod at high speeds, increasing EM current or oversizing the levitation system.

As a conclusion, the chosen layout for the levitation systems consists in 8 rings with 5 levitation units uniformly distributed along the pod length at the upper side.

Aerodynamics and Propulsion System

The Hyperloop Makers UPV proposes a propulsion system that consists in compressing the incoming air flowing along an inner tube up to a turbine that partially recovers energy and a nozzle that expands the air at the outlet of the pod producing thrust.

In the CFD analysis, the obtained results validate that the thrust needed to achieve cruise speed and to keep it constant is more than enough.

Additionally, this system allows braking with a constant deceleration by controlling the compressor discharge valve and/or compressor operating point.

At low speeds, the propulsion system consists of a mechanical traction mechanism of retractable wheels which is more efficient than the aerodynamic propulsion at these speeds.

Nevertheless, a complementary off-pod propulsion system could be proposed in order to reduce the energetic costs due to the initial acceleration and downsize the battery requirements.

At a cruise speed of 276 m/s (roughly 1000 km/h) the pod consumption per passenger is as low as 35 kW.

Guidance, navigation and control

The guidance and navigation system has been designed with multiple and redundant sensors with different technologies in order to achieve a fault-tolerant system. An optical mark system has been chosen to locate the pod. The distances between marks has been increased up to 200 m and an absolute positioning system has been added through the analysis of camera images. The controlled variables are pod-to-tube gap distance and pod attitude.

Safety

Every system has been designed with an alternative in case of failure as this kind of transportation system entails a lack of current regulation. This safety policy allows to prevent critical situations instead of acting after the emergency. Despite that, some corrective measures based on current aviation regulations have been considered as: oxygen masks, airbags or medical kits. Despite the efforts, a severe incident would almost signify passenger damage.

Costs

Due to the current pod design, the savings in the tube construction costs are fairly superior than the increase in pod price. For that reason, it is concluded that an on-pod system approach results in an economical advantage. Experiments and tests need to be carried out in order to confirm the theoretical conclusions obtained from the design proposal.

References