Naked Science Forum
On the Lighter Side => That CAN'T be true! => Topic started by: Lee Smith on 18/10/2009 12:30:03
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Lee Smith asked the Naked Scientists:
I am currently living on Roanoke Island North Carolina, (Home of the first English Colonization of the Americas) Driving across the waterways has led me to thinking...
Is it possible for a car to hydroplane across a deep pool of water. If so, How far? (I know there are people who do it in Snow Mobiles, and I think the record is around 105.74 miles).
What do you think?
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Wheeled vehicles have been driven across deep water, using the same principle as the snowmobiles you mention. The wheeled vehicles used for this rely upon having large and heavily treaded tyres to achieve the effect and act more like paddles than wheels; ordinary road tyres wouldn't work.
It basically comes down to Reynolds Numbers, which describe how apparent viscosity changes according to speed. In true hydroplaning you have an object moving at such a speed across the surface of the water that its viscosity appears to increase to the point where it acts like a solid and can't move out of the way quickly enough. With the snowmobiles and the large wheeled vehicles that drive across water what is happening is that the tread is being moved at a sufficient speed to achieve the same effect.
Ultimately, the distance you can travel like this is only limited by the amount of fuel you can carry, although to keep the wheels turning quickly enough usually means driving more or less flat out, which of course, uses a lot of fuel.
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Yes ... [:0]
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Yes ... [:0]
GORDON-BENNETT!
These folks in Iceland must have good health insurance!
I'm not sure the four-wheel drive vehicle is technically hydroplaning, or planing. I think the reason it stays afloat is because it has enough power to make each wheel continuously "climb" out of the water. Notice how the tires (tyres?) are modified to incorporate water scoops so they can pump a lot of water. If the tires were smooth, it would not matter how much power the vehicle produced - it would sink like a rock.