Hilda Margeret Lyon, aero-hydrodynamics
 

Here's a 'giant' who's shoulders we stand on:https://womenengineerssite.wordpress...nd-submarines/
PS: I apologize for misspelling her name. 'Margeret' should read 'Margaret.'

Airships are making a comeback. My friends company is making these in Finland:

https://kelluu.com/

Some cool things you can do with those that are not possible with other flying machines

So what holds them up? They talk about 12 hours of silent operation on Hydrogen, but nothing on the airframe or lifting medium.

I think its just a helium filled foil balloon at least the first versions. No frame needed as just the ball is inflated and has proper pressure to keep its shape.

camera equipment used does not weigth so much nowdays.

Problems with batteries only is the cold climate. Last week in Finland-30 to -40 celsius

Rumor has it the state of the art is metallic aerogel vacuum loitering drones.

' Hilda '
 

If this link works, you'll be looking at the German AIP, one-man, 'Delfin' ( dolphin ) midget sub, it's design influenced by the 'Lyon Shape.'
You'll notice that the hull of the sub is in constructed from 5-elements. The '3rd' element from the 'nose' is just a cylindrical extension, to give some extra space for the pilot.
If you remove this section, and rejoin nose and tail without it, it produces a streamline body of revolution with fineness-ratio of 3:1, which produces a drag coefficient near the drag minimum known.
You see a very generous transition zone, where the rear downslope leading to the trailing edge evolves very gently, in one continuous, uninterrupted contour.
This produces the favorable pressure gradient necessary for attached flow, and pressure recovery responsible for lowest drag.
This is the whole premise for 'streamlining' and 'aerodynamics.'
It's no surprise that those specializing in streamlining are getting 'dosed' with this technology. It's the 'Golden Goose.':)
H I Sutton - Covert Shores