| basjoos |
07-20-2006 03:45 PM |
Quote:
Originally Posted by Gary Palmer
Cool! So, it doesn't seem like a mushroom shape would be very efficient, does it? One thing I've always wondered about is that in sailing, their is a hull speed which is largely related to the length of the boar. If I am sailing a 22 foot boat, about the best speed I can make is 4 to 4 1/2 knot's. If I am sailing a 35' boat, I can make more like 6 - 6 1/2 knot's. It seems like their might be a similar phenomenon with the wind, but the barrier is not generally so noticible as it is with a boat. Anyway, something of curiosity.
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The effect of higher speed with longer hull length of a displacement hull is a result of the speed of a wave with the length of that hull's waterline. The longer the wavelength of a wave, the faster it moves through the water. When in motion at its maximum economical speed, a displacement hull is generating a wave the length of the ship's waterline. The bow of a displacement hull is at the peak of one wave (the bow wave), the center of the boat is at the wave's trough, and its stern is at the peak of the next wave. This is why racing shells are so long and narrow. |