Part of the vehicle?

[TransformerRobot]

Is a hovercraft's skirt a part of the vehicle itself? I'm asking because somebody else online just said this:

 

"A flexible skirt around the bottom of the pressure plenum will confine the air pressure, ride over small obstacles, and lift the whole assembly higher."

 

He said "the whole assembly", which I thought meant the hovercraft's body. Does this mean the skirt is not a part of the craft itself? I thought it was because it was still attached to the vehicle.

[EdEarl]

IMO the skirt is part of a hovercraft.

[pwagen]

Are a car's wheels parts of the vehicle itself?

Edited June 6, 2013 by pwagen

[Phi for All]

The skirt helps contain and increase the air pressure, focusing it downward only, so it lifts the whole craft a bit higher, including the skirt which is attached. That's the way I read it.

[TransformerRobot]

My thoughts too. The skirt still touches the ground too much for it to actually hover, at least in my opinion. I still even see clouds of dust or mist trailing behind these craft. Or is that for another reason?

[Externet]

Yes, the skirt is part of the hovercraft; contains the air pressurized by a fan blowing into its plenum.

 

The fan inflates it, stretching its height to the limit and raising the vehicle because of the pressure built-up. At the limit of rise, air escapes. The dust/mist is caused by the speed the air escapes between the gap, between the skirt bottom and the riding surface. The smaller the gap, the faster the flow. There is mild abrasion as the skirt bottom contacts the riding surface bumps.

 

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[TransformerRobot]

Do you mean an abrasion of the skirt or of the air pressure?

[arc]

I'm curious, is smooth water or smooth land a more efficient surface for these craft? I would think smooth pavement with several centimeters of water (4 for lighter craft and up to 12+ for heaver machines) would work best. I would expect deeper water would begin to pulsate from irregular movements in the platform that would be amplified by the waters density vs the machines buoyancy. But this assumption could be wrong due to what has less friction on the skirt, pulsating water or dry pavement? I think I like smooth ice.

[dimreepr]

Any smooth surface will give very similar results, however, the relative smoothness of the surface is dependent on the size of the vehicle; for instance the passenger hovercraft could cope with reasonably choppy seas, with which a single person craft couldn’t possibly cope.

Edited June 8, 2013 by dimreepr

[Externet]

Abrasion of the skirt edge. It does make contact with rough soil surface.

 

The smoothest ride is on a frozen lake. Smooth land is more efficient, as the soil does not deform under the craft as water surface does, making it more concave at lower speeds. Riding on an even slightly inclined pavement makes very difficult to maintain heading. A calm river is a very pleasant ride.

 

Find somehow to ride on one, and you may get hooked. And do not bring the throttle down on fast turns ! You may rollover ! It will be noisy and wetty...

[TransformerRobot]

Would a hovercraft work on sand dunes?

[arc]

Abrasion of the skirt edge. It does make contact with rough soil surface.

 

The smoothest ride is on a frozen lake. Smooth land is more efficient, as the soil does not deform under the craft as water surface does, making it more concave at lower speeds. Riding on an even slightly inclined pavement makes very difficult to maintain heading. A calm river is a very pleasant ride.

 

Find somehow to ride on one, and you may get hooked. And do not bring the throttle down on fast turns ! You may rollover ! It will be noisy and wetty...

I think I'm hooked already.

 

Would a hovercraft work on sand dunes?

I would assume no due to the degree of slope and lack of power in most fan driven vehicles, but a smooth beach would work well. But sand and high speed wind generating machinery makes for an airborne cloud of particulates. Sand is hard on mechanical systems. The faster a component moves the more erosion of material will occur in a given time period. The blades of the fan assembly are highly vulnerable along with any unsealed bearings. Surfaces that are exposed to the high speed sand can also erode quickly. The machine would need to be built of materials that could resist this abrasion. A rubber coating could resist most lower speed abrasives but engines and blades are still vulnerable. arc

Edited June 9, 2013 by arc