What is a hydrofoil? A hydrofoil is a watercraft that is supported on ski-like pontoons while in motion, with the bulk of the hull remaining entirely above the water (Encarta Encyclopedia 2002). Hydrofoils were first seen about in 1869. Emmanuel Denis Farcot was issued a patent on a boat that he had developed to go faster through the water because of less resistance. If you look at his design, he was using many little foils along the side of his boat to lift it out of the water in order to reduce the drag on the hull of the boat.
Hydrofoils are not only used on boats. Guidoni and Croco took the idea of hydrofoils and put then on seaplanes. Their main reason for puting foils on the plane was to make the landings smoother and to make takeoffs much quicker. The plane can get out of the water much faster with foils because there is less drag inhibiting the plane from gaining speed to get airborn. This is useful when taking off of short lakes or in rough water.
There are many purposes for hydrofoils. The main reason people or buisnesses install hydrofoils onto their watercraft is to decrease the drag of the boat as it travels through the water. By decreasing the drag, the watercraft is able to travel at higher speeds while burning less fuel. This makes use of the watercraft much more economical and provides a smoother, more comfortable ride because the watercraft rides above the reach of most of the waves.
Another reason to use hydrofoils is because they are fun. The picture below shows a water ski that has been transformed into something that you sit on with your feet in front of you while you are "floating on air" behind a ski boat.
When used on sail boats, hydrofoils can increase the top speed by quite a bit. Once the hull of the sail boat is out the the water the drag from the water is much less. Simply explained, there is less surface area "rubbing" on the water to slow the boat down. This means that even with gentle winds, a small boat can really get moving.
Most hydrofoils lift the watercraft that they are supporting in the same way that airplane wings keep the plane supported in the air. With enough lift on the water foils, the hull of the watercraft is lifted out of the water.
Slingshot diving fin comes with some innovations such as Gear Shift, Mid-foot Flex Joint, and Power Bands, which are specially designed to provide a great experience while diving. Power Bands are equipped with a pure silicone that provides a boost of energy on the power stroke and reduces fatigue. That allows you accumulate energy and reclaim it prior to the upstroke rather than wasting your energy like with some other diving fins.
Personal Watercrafts or "jet skis" are basically Personal Watercraft (PWC) are basically small inboard boats able to travel at high speeds due to large amounts of power and very light weight. Alomst all PWC's are under 600 lbs and most of todays PWC's have at least 90 hp.Not only are PWC's some of the fastest water vehicles they are also some of the most maneuverable water vehicles. This is because PWC's propultion is based on a jet that also is it's turning mechanism. When the driver turns the handlebars the jet (via cables) turns in the direction of the handlebars so the stern is pushed in the opposite direction. This allows the driver to turn at a much tighter angle than traditional boats with keels and rudders.The main drawback to this maneuverability is the fact that if there is no thrust coming from the engine the ability to turn is effictively zero meaning that anytime the driver presses the kill switch (a large red button) they lose all ability to steer. This is extremely dangerous whenever an inexperienced person may drive the PWC back to dock or into shore. PWC's have no brakes and have no ablilty to stop other than turning around. They have an extremely efficient ability to hydroplane (when most of the PWC is above water) and it takes most PWC's a few hundred feet to come to a stop after being at full throttle. This is because 600 lbs + a rider is traveling at a very high speed with only minimal friction to slow them down (since PWC's are made to travel with very little friction).
Skin resistance, wave resistance and turbulence resistance are three main types of resistance relating to humans and water. A layer of fluid is formed (boundary layer) on the skin which is in direct contact to the water, when the swimmer moves in one direction the Boundary layer interacts with the preceding layer of water gripping tightly. This creates a frictional force preventing forward movement without further propulsion, consequently called ‘Skin Resistance’. Wave resistance is a build up of fluid in front of the swimmer creating a high pressure zone, the faster the swimmer can travel the higher the pressure is in front of them. This pressure can be reduced by using appropriate streamline techniques causing less displacement of laminar flow. Turbulence resistance is the displacement of laminar flow, when swimming you create a high and low pressure zone causing a suction effect. Using efficient streamline techniques the water displacement is minimized and less eddie...
Displacement hulls were first used at the turn of the century when internal combustion engines were large and heavy. Morley S. Smith - lesliefield.com. When a displacement hull moves through the water, it pushes water off to the sides. Most displacement hulls are long with a narrow bow. These hulls are the easiest to maneuver at low speeds. Semi displacement hulls are slightly more flat. Semi displacement hulls are identified by three factors: 1. The shape of the run. 2. The displacement length ratio. 3. The amount of “V” or draught of the hull and they generally have a hard chine or tightly rounded bilge. - Pelly Marine. Semi displacement hulls are versatile and combine speed and seaworthiness. Planing hulls are hard chinned and have a sharp edge between the hull side panel and the side panel. Morley S. Smith – lasliefield.com. When planing hulls are moving they push the bow downward instead of pushing water to the sides like displacement hulls. It was discovered that if you have a flat bottomed boat there will be less drag. The less drag the boat has the smoother the ride on the boat will be and there will be less of an attack angle to the boat. Most of the planing hulls today are made with a vee bottom. The height and weight of have have great effect on the speed. Planing hulls tend to skim more on the water rather than moving in the water. The concept of the stepped hull was proposed by Rev. Ramus of Sussex, England in 1872. He proposed both a single stop with tandem planing surfaces, and a combination of three pontoons with one forward and two aft. Morley S. Smith – lasliefield.com. After figuring out the steam power was not powerful enough to move the hull fast enough, William Henry Fauber move to Europe with this idea in ...
Running rigs are used to manipulate sails. Halyard, sheet, boom vang, toping lift, roller furling, downhaul, and traveler are types of running rigs.
Riblets and tripwires are widely explored and documented structures that have a huge potential for use in drag reduction technology. Passive strategies for drag reduction in air and underwater vehicles, such as airplanes and submarines, are increasingly being investigated as they reduce the cost of operation of the vehicle by increasing its speed and efficiency. This essay discusses riblets and tripwires, and their use in drag reduction technology. Their optimal specifications, mechanism of functioning and potential applications for drag reduction over underwater aerofoils have also been dealt with.
Throughout history paddling has been characterized by the various situational opportunities presented in that day, in time. Recreation, Transportation, Traveling, Competition, Exercise, and Fishing are just some of the ways paddling has been seen throughout history. Along with the activities that go on with paddling, different types of canoes and kayaks had to be made to keep up-to-date with these activities evolvement. Beginning more traditional with a dugout canoe and ending more advanced with the numerous racing canoes, our world has in fact grown to new developments. Kayaks on the other hand are similar in the way that they have progressed through history, however, the boats are all based on the idea of measurements,
During my visitation I explored my mentor, Bob Waller’s, workshop where he builds his company’s boards. He explained to me all the distinct deck shapes and the riding styles for those deck shapes. I learned from my visitation that longer decks are usually used for carving and pumping similar to the shape of ride style of a surf board. Slightly shorter boards are usually used for hill bombing and slightly shorter than those are primarily reserved for freestyle and free riding. Some decks can also be lowered or commonly known as drop down. I learned from my research that these lowered decks can provide more stability because the rider’s center of gravity would be lower. Therefore drop down decks are usually used for freestyle
Its easier to start at an earlier age at the beginning of the 13th century surfing fell out of favor but is now booming and wind surfing is very popular because it was banned by the government because of the dangers of it but now is legal and almost every able bodied person does it as a stress reliever or a time
Flight is one of the most important achievements of mankind. We owe this achievement to the invention of the airfoil and understanding the physics that allow it to lift enormous weights into the sky.
“Drag reduction is a high-priority goal of [aircraft] designers.” (textbook, pg 25) By reducing the spanwise flow at the wingtip, winglets are therefore able to weaken vortices and significantly decrease drag. During cruise, minimal drag means maximum performance. Winglets are now quite common in the aviation industry, making them, “…one of the most successful examples of NASA aeronautical innovation being utilized around the world on all types of aircraft.” (nasa.gov).
Kites have existed for many years but multi-line kites were not even invented until around 1826. People use these multi-line kites for pulling just about anything from kite boards, surfboards, skateboards, roller skates, and skis. The biggest setback for kiteboarding was whenever the riders kite hit the water it would not relaunch because of the material used to make the kites would soak up the water and become too dense to fly through the air. Then Bruno and Dominique Legaignoux came up with the idea of an inflatable kite that would relaunch even when it was soaked in 1982. This helped to increase the popularity of the sport of kiteboarding which did not really emerge until the late 1990’s. Kiteboarding has many names and nicknames but the most common names are kiteboarding, kitesurfing, and fly kiting. The sport did not start to become popular until the 21st century. Ever since then the sport’s participants have increased rapidly throughout the years as it has evolved into the sport we all watch from the shore side. (Terry)
From the humble beginning of the kayak as a hunter’s boat in the Arctic, to the olympic stage of competition, the kayak has become a modern vessel for voyages both near and far, and has become one of the most popular modes of transportation on the water as a recreational hobby for many.
Next, hydro-electricity is electricity produced by moving water, flowing past a turbine connected to a generator (“Hydropower”). According to Nationalgeographic.c...
Advantages of wind turbines offshore in the Mid-Atlantic: Each one of us has their own opinion about what wind turbines do and not what they are actually meant for. Wind turbines are meant to be an energy saving method that can be used offshore in the water or on land. In this case we are talking about having them in the water and in specific offshore in the mid-Atlantic.... ... middle of paper ... ...