Bringing the Hyperloop One Step Closer to Reality Through Simulation

It sounds like something out of Star Trek or Buck Rogers, but the notion of a super-fast (think speed of sound or faster) ground-based transportation system isn’t science fiction.

About a month ago, Elon Musk, the visionary behind ANSYS customers SpaceX and Tesla, formally proposed the Hyperloop, which would transport people via aluminum pods enclosed inside of steel tubes. These pods would travel up to 750 miles per hour, shrinking travel time between cities. (A trip from Los Angeles to San Francisco would be only 30 minutes!)

But as it often happens when a true innovator steps forward with a new idea, the critics descended. They claimed the Hyperloop was nothing more than mere fantasy, that it wouldn’t be practical. Even Musk himself admitted that prototypes were needed before he could turn the Hyperloop into reality.

I’ve been personally interested in the idea of this potential mode of transportation for some time now. In my opinion, the technologies needed for implementing tube transportation are extremely simple, compared to some of the highly sophisticated machines such as commercial airliners or spacecraft that humans routinely construct today.

So, using ANSYS technology, we put Musk’s Hyperloop designs to the test. The upshot? The Hyperloop will indeed work – with some tweaks.

The first issue we found in the virtual prototype was with airflow. The pod shape that Musk shows in his white paper will cause some of the air around the vehicle to become supersonic, which could lead to a completely different class of engineering problem and make hyperloop infeasible. With some adjustments – increasing the taper of the front and back ends of the pod, the airflow would be subsonic and wouldn’t choke as it moves past the vehicle.Hyperlook Contours of Velocity Magnitude

The other major issue that our simulation illustrated was related to the amount of air sucked by the front fan and how and where that air is released. A significant portion of that air could be released through the air bearings to keep the vehicle afloat and friction free. But that air can severely disrupt the pod’s aerodynamics, again possibly leading to choked airflow. The location of bearings, the shape of the pod and the amount of air flowing out of the bearings, all will have to be carefully balanced to make the design feasible. However, these challenges are fairly routine in engineering development and I don’t anticipate any major problems in solving them. Several more virtual prototype tests, and the balancing will be done, even before a physical prototype is sketched on the drawing board!

Hyperloop Contours of Wall Shear Stress

Optimizing high speed vehicles by studying aerodynamics of virtual prototypes is a well proven technology today. For instance, Red Bull optimizes aerodynamics by studying hundreds of virtual prototypes to making winning Formula 1 cars. I’d recommend that you visit our Red Bull page and download the whitepaper Cutting Design Costs: How Industry Leaders Benefit From Fast and Reliable CFD to get a further explanation on how it is done.

Today we are at a point where we were 200 years ago, when railways were just on the horizon. Railway technologies were all but ready and being fine-tuned while millionaires with mega visions to build transcontinental railway lines were beginning to muster the courage to make the risky investments needed for constructing infrastructure of magnitudes never before seen. Just as the railways spread rapidly after that point and crisscrossed the continent within 50 years, I am highly optimistic that in the next 50 years our mode of transportation will have fundamentally changed to tubelines, making transport incredibly fast. After all, I am eagerly waiting for the day when I can live in Florida and commute in half an hour to my day job in Michigan!

This entry was posted in Automotive, Fluid Dynamics and tagged , by Sandeep Sovani. Bookmark the permalink.

About Sandeep Sovani

Dr. Sandeep Sovani is Director for the global automotive industry at ANSYS. He holds a B.E in Mechanical Engineering from University of Pune, India, M.Tech., from Indian Institute of Technology Chennai, India and Ph.D. from Purdue University, USA. Dr. Sovani has been actively involved in various areas of automotive technology and business for two decades. Dr. Sovani has previously worked with Tata Motors, India. Under a grant from the Cummins Engine Company, he has conducted research on IC Engines at Purdue University and recently served as an Adjunct Professor of Engineering at Lawrence Technological University, Michigan, USA. Dr. Sovani has authored more than 40 papers, articles, reports and has delivered numerous invited lectures at academic and industry conferences. He is the recipient of Lloyd Withrow Distinguished Speaker Award from SAE International (Society of Automotive Engineers). Dr. Sovani is also the founder of Hybrid Electric Vehicles Michigan group, a professional networking group of HEV engineers, and its sister groups in Brazil and UK. Dr. Sovani presently is member of SAE International and serves as a technical session chair and organizer on the society’s vehicle aerodynamics committee. Dr. Sovani is also a member of the American Society of Mechanical Engineers (ASME), Sigma Xi, MENSA International, and other societies.

4 thoughts on “Bringing the Hyperloop One Step Closer to Reality Through Simulation

  1. Did your hyperloop simulation showing supersonic air streams around the car module look at speed relative to static air as in a wind tunnel or take into account relative speed of the module and air circulating in the tube in which several modules are simultaneously traveling? I would think that friction with the tube walls would cause the speed of air circulating in the tunnel to be fastest in the middle and slowest at the walls.

    This would, I speculate, allow the Bernoulli effect to pull air toward the center away from the walls and reduce friction with the walls to some degree. Concentration of air in the center of the tube would favor the compressor in the module front and reduce the air flowing around the module.

    I happen to know that sharks pump water through pores in their skin to reduce water friction and make swimming more efficient. This seems to imply that the friction of pumping water through their pores is more than compensated by the reduction in friction against forward motion. Interestingly, this also implies that this remains true although the pores represent only a fraction of the skin surface. It is also well known that there is a multiplier effect when strong air streams are pumped into static air.

    I’m therefore wondering whether there might be an advantage in letting some portion of the air pumped out through the air bearing skis exit all around the moving module instead of strictly through the skis.

  2. Pingback: Is Hyperloop a Hyped Dream or Practical Design? ANSYS Weighs In | Virtual Desktop

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