Info on hydrogen and (tethered) hydrogen aerostats

[Windy_Skies]

Related topics: AWES using LTA with PV for hydrogen production on board

Is an electrically heated balloon lift support for AWES possible? .

I’ve lost interest in the idea from the first post. I’d like to now explore the idea of just using a hydrogen balloon instead of, or in addition to, lifter kites a bit more.

@kitefreak

A new balloon is effectively gas-tight but delicate, and soon develops tiny leaks over time that relentlessly dilute the lifting gas, with no easy solution. Thermal cycles and general envelope motions help push lifting gas out and air in.

I used to store micro-blimps in a dark quiet stable temperature room, nose-up, and only replace the bottom gas, with its higher air content, from the tail-cap.

Fluke ii900 Sonic Industrial Leak Detect Imager with Adam Wysor

Comment under video: Awesome tool. We have one at work. We use for chasing leaks during aircraft pressurization tests.

Something in the air: Ultrasound for compressed-air leak detection

Perhaps you could do pressurization tests of balloons too. Like this for example:

@Windy_Skies

If you temporarily want to increase pressure, you could add ballonnets inside the balloon and then fill them with nitrogen for example. After the storm has passed you could vent the nitrogen.

@PierreB

Indeed the process of endosmose is the main obstacle.

“endosmose” is the archaic form of endosmosis. It is not the right term for this phenomenon I think. The book is also from 1840, technology has moved on.

Because you will always try to have a higher internal pressure than atmospheric pressure, gas should flow out, not in.

@Windy_Skies

If you want to make a balloon that is able to withstand higher winds you would already increase the pressure inside to withstand deformation from the wind, and you’d perhaps limit the size so you can increase internal pressure more with identical thickness of envelope material. You could also make the balloon more into the shape of a teardrop (1) instead of a sphere.

Also permeability of an envelope to hydrogen is much higher than permeability of that envelope to air. So instead of air seeping in, you would sooner see the balloon just deflating. But of course you’d have a pressure gauge inside the balloon to measure pressure and if it became too low you’d either inflate a ballonnet to increase pressure again or take the balloon down for inspection.