Virgin Hyperloop One

[Shepherd777]

Does anyone care to elaborate about the rear of the pod profile regarding trailing edge aerodynamics?

Do they gain all of that ultra-low aerodynamic drag due mostly to the low pressure inside of the tube?

Their web site says: "With Virgin Hyperloop One, passengers and cargo will be loaded into a pod, and accelerate gradually via electric propulsion through a low-pressure tube. The pod quickly lifts above the track using magnetic levitation and glides at airline speeds for long distances due to ultra-low aerodynamic drag."

https://www.virgin.com/richard-brans...-train-service

[kach22i]

Most of these schemes are base on a vacuum in the tube because the air displaced would have to go somewhere as the capsule passes, so you want as little as air in there as possible - what air is in there is going to get squeezed and that takes energy.

The more air, the more energy because of air resistance.

Conclusion, the tail isn't treated with a cone or tail because there is so little air in the tube to begin with.

That's my guess anyway.

I sure would feel better about my opinion if I saw some CFD images video and gifs on it.

EDIT: I did find this................Musk's Pod, a different shape than Virgin's.

http://www.ansys-blog.com/20130925hyperloop/

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.

EDIT-2: Found more, plus this link has a video.

https://www.rs-online.com/designspar...ex-competition

https://www.youtube.com/watch?v=6Ea8ly18uzs

[JockoT]

The Hyperloop runs in a partial vacuum so you could pretty much get good aerodynamics from a brick.
I specialised in High Vacuum from the 1970's to the 90's, and once you get to low pressures, there is virtually nothing in the tube. Air resistance is virtually nothing. Mind you, even satellites, in orbit, are subject to aerodynamic drag. Just not a lot.