Height stability of Balloon Chair flyer

[wanabigaplane]

You’ve all heard of a man who tied lots of balloons to a chair and set off on an aerial adventure. I believe a priest set off about six months ago, and I haven’t heard of him being found.

 

Question 1: Would the aircraft rise to a certain height and then become fairly stable at that height, or would it continue to drift upwards till some balloons burst?

 

Question 2: If the pilot popped a few balloons to reduce altitude, would the aircraft become stable at a new lower altitude, or would it, once on a downward trajectory, accelerate downwards out of vertical control? :ah_oh:

 

Consideration: As a balloon is inflated, it takes less pressure to inflate the balloon. Why is it so? Well, the material making up the balloon gets thinner.

 

Jack. :):)

 

 

[facthunter]

Considerations

 

Hi Jack, The upper absolute limit would be a vacuum, as you are not displacing any air molecules and therefore do not get any "floatation effect".

 

Air density then becomes a very important consideration, but also the volume is not constant because as you ascend the balloon expands due to the reduced pressure. If you consider the elastic properties of the container (the rubber skin), you introduce another factor, that the gas inside the balloon is at a pressure equal to the atmospheric pressure at that height PLUS the pressure to inflate the balloon to the size it achieves. REAL balloons for records etc. operate part-filled near the earth to reduce the pressure.

 

Density and pressure changes with altitude are not linear, as an example, HALF the molecules in the atmosphere are below you at approximately 18,000 feet. You do not enter a vacuum at 36,000'.

 

I CAN"T ANSWER the second part, MY brain hurts.. Nev..

 

 

[Guest ramcam]

that was a while ago. He was the only man who survived to win the darwin awards. Apparently he floated into restricted airspace. Wouldn't it be a hoot to look out your 747 window and see a bloke floating along in chair!

 

 

[Yenn]

How did he win the Darwin award if he died?

 

 

[slartibartfast]

I think he meant that he was the only guy to get a Darwin award without having to die for it. They figured it was only a matter of time anyway.

 

Ramcam, the one Jack was talking about was a Brazilian priest who tried it for charity last April. The search was called off about a week later. They found lots of floating balloons, but no priests.

 

The one you refer to was in California years ago. He was rescued.

 

 

[wanabigaplane]

Clusterballooning - almost a sport

 

Quite a few have flown under helium balloons, and it is almost a sport now.

 

It only took a bit of Googling to find the following:

 

Larry Walters in 1982 at San Pedro spent 14 hours in the air. He wasn’t the first, he just got the publicity.

 

Kevin Walsh in 1984 at Stow, Massachusetts spent 45 minutes in the air.

 

Kent Couch in 2007 at Bend in Oregon, travelled 193 statute miles.

 

Reverend Di Carli in April 2008 sets out on his second trip, this time a fund raiser, at Paranagua in Brazil. He last gave his position by radio as 50 miles out to sea, and only his balloons have been found. He was an experienced hot air balloonist, and he had flown with helium balloons before.

 

The sport seems to have become known as ‘cluster ballooning’ and flights are now quite frequent.

 

See www.clusterballoon.org

 

Buoyancy characteristics don’t seem to be mentioned, but it seems the successful balloonist depends on having enough ballast to arrest his descent. It seems the early balloonists got into trouble because they had not prepared themselves for this.

 

Jack. :):)

 

 

[BigPete]

So............

 

What goes up, must come down. :ah_oh:

 

and

 

Take off is optional, landing is mandatory, :confused:

 

and

 

It's better to down here wishing you were up there, than up there wishing you were down here.

 

and

 

I bet most balloons these days are "Made in China"..................

 

:big_grin::big_grin::big_grin:

 

regards