Re: Inflatable Rotors (Flying Car?)

[Mark Hickey]

(sanman) wrote:

>I was reading about inflatable wings:
<snip>
>So you'd be riding a sort of lightweight automotive vehicle along the
>road, and you could switch to helicopter mode, with inflatable rotors
>popping out on the top of your vehicle. Your engine would then power
>the rotors, and you'd fly away. Once you landed again, the deflated
>rotors would be tucked back into whatever compartment they'd popped
>out from.
>
>Cmon, there are all kinds of wierd-looking lightweight concept cars
>out there, so why not this? What would be the main difficulties with a
>concept like this?

I think perhaps Barnyard BOb would be the one to give you the best
feedback on your idea...

Mark Hickey

[AnyBody43]

Mark Hickey > wrote in message >...
> (sanman) wrote:
>
> >I was reading about inflatable wings:
> <snip>
> >So you'd be riding a sort of lightweight automotive vehicle along the
> >road, and you could switch to helicopter mode, with inflatable rotors
> >popping out on the top of your vehicle. Your engine would then power
> >the rotors, and you'd fly away. Once you landed again, the deflated
> >rotors would be tucked back into whatever compartment they'd popped
> >out from.
> >
> >Cmon, there are all kinds of wierd-looking lightweight concept cars
> >out there, so why not this? What would be the main difficulties with a
> >concept like this?

Given that centrifugal force keeps the rotors from folding upwards
anyway it seems a relatively small change in the principles of operation
to have such a mechanism.

If inflatible was no good how about folding/telescopic . . .
or just ribbon/strip with a weight on the end.


## Miniature emergency parachute hat ##

Since the "wing" area of a helicopter is much less than that of
a parachute, and that a helicopter CAN land softly without an engine
why not have a small device that:-

Is an auto gyro that infates out of a bag
Uses gas jets to accelerate the blades to operating speed
lowering the wearer safely to the ground.
Would be smaller and lighter than a conventional parachute?
Maybe a pyrotechic charge could be used as a gas source?

Perhaps a small hand grenade would be enough to get it going:)

[wmbjk]

"sanman" > wrote in message
om...
>
> So you'd be riding a sort of lightweight automotive vehicle along the
> road, and you could switch to helicopter mode, with inflatable rotors
> popping out on the top of your vehicle. Your engine would then power
> the rotors, and you'd fly away. Once you landed again, the deflated
> rotors would be tucked back into whatever compartment they'd popped
> out from.
>
> Cmon, there are all kinds of wierd-looking lightweight concept cars
> out there, so why not this? What would be the main difficulties with a
> concept like this?

Woodpeckers.

Wayne

[sanman]

Well, polymers and reinforcement fiber technology are continuing to
improve. You can even buy carbon-fiber reinforced polymers these days,
with superduper tensile strength. But I would imagine that kevlar,
spectra, vectran would have enough strength to do the job for a small
personal transportation vehicle. They would be able to handle the high
pressures.

To ease the load requirements, the rotor could be 4-vaned. Each pair
of opposing vanes could have a commonly inflated structure -- that way
if a single vane suffered a rupture, then it and its opposing partner
could be deflated/depressurized, while the remaining pair of rotor
vanes would take the load while you landed. Or why not even a 6-way
rotor?

Someone who responded to my posting suggested weighting the rotor tips
for flywheel effect. The centrifugal force from the weighted tips
would help to keep the rotors rigid and reduce the possibility of
buckling. Flywheel energy could also help in the event of an unpowered
landing due to engine failure.

[Dan & Jan Hollenbaugh]

I don't recall inflatable wings, but both telescoping and "ribbon" blades
have been tried. IIRC, the cloth rotor had a wire "spar" with a tip weight,
and a cloth single panel sail-like "blade". Also IIRC, the idea was to use
it in autorotation mode, as a deceleration device in place of a parachute.

Rigid telescoping blades have also been tried experimentally. The variable
diameter allowed for two flight regimes - high speed (with outer portion
retracted) and low speed (outer portion extended, more lift for hover
profiles).

I've got some info on my work computer, I'll try to post it later.

Dan Hollenbaugh
AnyBody43 wrote in message
>...
>Mark Hickey > wrote in message
>...
>> (sanman) wrote:
>>
>> >I was reading about inflatable wings:
>> <snip>
>> >So you'd be riding a sort of lightweight automotive vehicle along the
>> >road, and you could switch to helicopter mode, with inflatable rotors
>> >popping out on the top of your vehicle. Your engine would then power
>> >the rotors, and you'd fly away. Once you landed again, the deflated
>> >rotors would be tucked back into whatever compartment they'd popped
>> >out from.
>> >
>> >Cmon, there are all kinds of wierd-looking lightweight concept cars
>> >out there, so why not this? What would be the main difficulties with a
>> >concept like this?
>
>Given that centrifugal force keeps the rotors from folding upwards
>anyway it seems a relatively small change in the principles of operation
>to have such a mechanism.
>
>If inflatible was no good how about folding/telescopic . . .
>or just ribbon/strip with a weight on the end.
>
>
>## Miniature emergency parachute hat ##
>
>Since the "wing" area of a helicopter is much less than that of
>a parachute, and that a helicopter CAN land softly without an engine
>why not have a small device that:-
>
>Is an auto gyro that infates out of a bag
>Uses gas jets to accelerate the blades to operating speed
> lowering the wearer safely to the ground.
>Would be smaller and lighter than a conventional parachute?
>Maybe a pyrotechic charge could be used as a gas source?
>
>Perhaps a small hand grenade would be enough to get it going:)