Splashing is just another way of saying you are moving a small amount really fast. So to avoid splashing, you want to want to avoid applying power until the paddle blade is fully submerged. But you don't want to wait too long otherwise your stoke will be over before you really started.
So you should try to submerge the paddle quickly so you can apply power as long as possible. Whenever you are not applying power, your boat is slowing down and the slower it gets the more effort required to bring it back up to speed. There is another reason for waiting before applying power - "Ventilation". Ventilation is what you call it when the paddle sucks air down the back of the blade. Many people call it cavitation, but that is when a propellor spins so fast that it creates a vacuum behind the blade.
Neither is any good, but what your average kayaker creates is ventilation. The reason it is no good is you are moving air instead of water. Air weighs a lot less than water and if there is air behind your paddle instead of water the mass of water you are moving is decreased and thus creating the same momentum requires you expend more energy. There are two ways of creating ventilation. One is by bringing the air down with the blade as you insert it into the water. The other is to pull air down the back of the paddle as you apply power.
Both can be avoided by being sure your blade is fully submerged before applying power. A clean entry will not bring down much water and the small area near the top of the blade is less likely to ventilate. You can also waste energy at the end of the stroke.
Again it will be indicated by splashing. If you still have a paddle full of water when you pull it out you will end up throwing it. This will often happen if you are applying power all the way until the paddle is removed from the water.
Throwing water at best falls into the "moving a small mass fast" area at worst you are just lifting it and letting it drop straight down providing you with no momentum boost whatever.
If you are going to throw water around you at least want it moving in a direction opposite your direction of travel.
To reiterate, your basic paddle stroke needs several things to be efficient: a fast clean entry, power while the blade is deep in the water, followed by a quick clean exit. Then you need to get started on the next stroke as soon as possible before your momentum is frittered away in drag on the boat.
But I have left out an important point: where you put your paddle. A force is applied directly through the geometric center of the mass of the object. When a force is applied to the side of the mass it is actually called a "torque". Torques have the tendency to rotate the mass they are applied to. Sitting in your kayak, your center of mass is in the center of the kayak and you are sticking your paddle out to the side.
The force of your paddling effort is actually creating a torque on your kayak. All your kayak really only wants is spin around its center. Turbine Flow Meter Verification. Flow Meter Installation Guide. Optical flow meter Principle.
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No comments:. Post a Comment. Newer Post Older Post Home. Paddle wheels are attached to vessels either at the rear large single units or at the sides smaller pairs. The wheels, while sometimes exposed, are more often housed within a container called a paddlebox. The speed at which a paddle wheel spins is dictated by a large industrial gearbox, which allows for a selection of drum rotation speeds in addition to a single speed reverse.
Certain paddle-wheel systems also come fitted with adjustable paddles. These work by separating each unit from the drum on axle-like rods — a mechanical layout that enables individual paddles to alter their angle upon contact with the water to be closer to vertical.
By doing this, each paddle generates a greater amount of thrust, increasing overall efficiency and power. Historically, paddle-wheel vessels were used as both ocean-going ships as well as riverboats. However, after the development of the modern screw propeller the paddle wheel was largely superseded due to its poorer efficiency in rough waters.
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