Optimizing a levitating rail-free pod design for SpaceX Hyperloop Design Competition

The Hyperloop Makers UPV team, from the Universitat Politécnica de Valencia, took part in the SpaceX international challenge for the development of the Hyperloop ultra-fast train and was awarded the Top Design Concept and the Propulsion/Compression Subsystem Technical Excellence Awards. The goal of the competition, launched by SpaceX CEO Elon Musk, is to perfect its revolutionary land transport system, driven by compressed air and to connect Los Angeles and San Francisco in 30 minutes.

Whereas the majority of the competing teams opted for passive magnetic levitation or designing the passenger pod suspended on air bearings, Hyperloop UPV developed a system that enables levitation through the magnetic attraction of the pod to the top of the tube. This rail-free solution saves up to 30% on Hyperloop tube construction costs.

modeFRONTIER helped the team select the optimum design in terms of travel experience, maximizing energy efficiency while accelerating design iterations and development time.

The engineering challenge consisted in providing the base design for a 30-passenger cabin travelling as fast as possible through a vacuumed tube. The technological solutions, in terms of comfort for the travelers subject to such high acceleration and cruise speed, were investigated by the team, assisted by advanced multiobjective optimization techniques. The proposed design for the Hyperloop pod uses an innovative magnetic levitation system. It consists of permanent magnets and electromagnets that can generate a controlled lift that enables pod levitation (figure 1). The propulsion system includes a front compressor moved by an electric motor that captures the air intake and delivers it to a nozzle in the rear of the pod. This nozzle produces the thrust for the system.

The computations related to the acceleration and cruise phase were set up in Excel and integrated into the modeFRONTIER workflow. The design variables mainly related to the compressor and the turbine (pressure ratio and discharge velocity) were automatically adjusted by the software to optimize the output results: acceleration time, specific energy required, pod mass and travel speed. The use of the multiobjective genetic algorithm (MOGA-II) led to the optimum solution that enabled maximum autonomous acceleration for the pod with the minimum required energy (figure 2). Moreover, optimization results for the cruise phase highlight the maximum travel speed with minimum energy consumption but also reduced pod mass (figure 3).

"The effects of modifying even a single variable were, at best, difficult to explain as the physical models regarding the behavior of the system were highly interconnected and interdependent. With a traditional approach, this fact would have lead to a slow and difficult system optimum. modeFRONTIER on the other hand, enabled the team to obtain a family of optimum solutions for a range of inputs in a mere fraction of the time” said Germán Torres (Technical Director at Hyperloop Makers UPV Team). In terms of specific energy per passenger/km, the results show the pod consumes ten time less energy and travels ten times faster than traditional road transport.

"We are developing a small levitation demonstrator for the next phase of the SpaceX international challenge", continued Torres, "in fact we plan use modeFRONTIER again to optimize the new Hyperloop design proposal".