Hilsch Tube for Cabin Temp control...

Hey Guys-

Has anyone ever attempted to install a Hilsch Tube (Vortex Tube) in an
aircraft for environmental controls?

The setup I see would be very light, a 3 foot long PVC vortex tube (no
more than 5 lbs) with a small exhaust turbocharger force-feeding it.
Yes the Hilsch tube is not a particularly efficiant cooling mechanism,
but exaust-gas pressure is essentially 'wasted energy' anyways.

It strikes me that controlling such a mechanism would be trivial
(baffle the hot-cold ends of the tube to a controllable valve, and then
into the cabin), lightweight, and relatively inexpensive...

IT seems to perfect, why hasn't anyone done it before? (Hilsch tubes
are already used as cooling mechanisms elsewhere.

quick wiki reference- plenty more can be found online-
http://en.wikipedia.org/wiki/Vortex_tube

-Scott

EridanMan wrote:

Has anyone ever attempted to install a Hilsch Tube (Vortex Tube) in an
aircraft for environmental controls?

I built one of them in High school as a science fair project. it
worked, but was noisy as hell. Usually, vortex tubes are used for spot
cooling, due to their low efficiency. One big enough to cool a typical
aircraft cabin would be quite large, and as I said, NOISY!

Steve

whoops continuing:

We're talking about using exhaust pressure energy that would be heading
out the tail pipe anyways, right?

Eh... its all 'armchair engineering', I know- just fun to think about.
I can definitely see how such a system might be useful (internal
climate control, wing anti-ice) if the engineering hurdles could be
worked out (noise, high enough input flow, weight (possibly))

EridanMan wrote:
Hey Guys-

Has anyone ever attempted to install a Hilsch Tube (Vortex Tube) in an
aircraft for environmental controls?

The setup I see would be very light, a 3 foot long PVC vortex tube (no
more than 5 lbs) with a small exhaust turbocharger force-feeding it.
Yes the Hilsch tube is not a particularly efficiant cooling mechanism,
but exaust-gas pressure is essentially 'wasted energy' anyways.

But, it's not really.
Adding extra back pressure to the engine decreases its efficiency.

And small, unpressurized airplanes don't need cooling. The air outside
is plenty cold. For heat, there's lots to be had from the exhaust or
oil with a simple heat exchanger.

In a pressurized airplane, I don't think the vortex tube would work. I
don't think you can exhaust the cold side into the cabin and the hot
side overboard, so I think you're back to conventional AC.

The very point of the Turbo is that a well designed turbine (matched to
the expected flow) do not significantly increase backpreassure, but
does harvest excess pressure energy.

This is the fundamental difference between Turbocharging and
Supercharging.

Yeah... You have a point about how useful it might be (especially for a
Bay area pilot such as myself)...

Although - The tube flow is pressurized, so there's no reason that a
hirsch tube setup could be used as the preassurization mechanism for an
aircraft (assuming the structure can handle it... big assumption)...
The only question would be could you maintain a comfortable balance of
warm and cold air...

I dunno... Probably more effort than its worth, i'll agree, but its
still fun to think about.

The flow tube is pressurized, but I'll bet if the cold side exit is at
a higher pressure than the hot side exit, the pressurized air inside
the cabin will just join the pressurized turbocomressed air in exiting
to the outside atmosphere.

I bought 2 surplus factory made tubes to experiment with. One thought
was to use some of it's cooling to blow on the radiator and intercooler.
They aren't very large and I don't have a pressure graph for them. It
is fun to tinker, though.

David M.


EridanMan wrote:

Hey Guys-

Has anyone ever attempted to install a Hilsch Tube (Vortex Tube) in an
aircraft for environmental controls?

The setup I see would be very light, a 3 foot long PVC vortex tube (no
more than 5 lbs) with a small exhaust turbocharger force-feeding it.
Yes the Hilsch tube is not a particularly efficiant cooling mechanism,
but exaust-gas pressure is essentially 'wasted energy' anyways.

It strikes me that controlling such a mechanism would be trivial
(baffle the hot-cold ends of the tube to a controllable valve, and then
into the cabin), lightweight, and relatively inexpensive...

IT seems to perfect, why hasn't anyone done it before? (Hilsch tubes
are already used as cooling mechanisms elsewhere.

quick wiki reference- plenty more can be found online-
http://en.wikipedia.org/wiki/Vortex_tube

-Scott