HYDROFOILS & HOVERCRAFTS

WHO KNOWS WHAT A HYDROFOIL IS?

WHAT IS A HYDROFOIL ? A Foil is another word for a wing. A Hydrofoil is simply a wing that “flies” in the water. Hydrofoils let a boat go faster by getting the hull out of the water.

HISTORY OF A HYDORFOIL The first Hydrofoil vessel was built in 1905 by the Italian engineer Enrico Forlanini. In 1918, Alexander Graham Bell built the HD-4, a hydrofoil vessel 60 ft long which attained a speed of 70.86 mph. BELL – HD-4

HOW DOES IT WORK? When a boat moves forward, most of the energy used goes to moving the water out of the way. The Hydrofoils special design lifts the hull of the boat out of the water to reduce the drag, which increases speed and fuel efficiency.

Detail of Pressure At Points Over An Airfoil                                                                             Detail of Pressure At Points Over An Airfoil HOW DOES IT WORK? Hydrofoils lift the watercraft the same way that airplane wings keep the plane supported. Foils create lift when the water traveling over the top goes faster than the water traveling over the bottom Where there is faster velocity, there is lower pressure.

HOW DOES IT WORK? The higher pressure on the bottom of the foil causes the lifting force needed. The lift can be optimized by positioning the hydrofoil at an angle (angle of attack).

                                                                                                          Detail of Hydrofoil: a) Pressure Profile    b) Momentum Transfer    c) Circulation     d) Streamlines

COMMERCIAL USES Cargo Vessels: Passenger Vessels: Military Vessels:

RECREATIONAL USES Sailing: Wakeboarding: Air Chairs:

WHO KNOWS WHAT A HOVERCRAFT IS?

WHAT IS A HOVERCRAFT? A Hovercraft is a vehicle supported on a cushion of air supplied by a powered fan mounted on the back of the vehicle. AKA: Air Cushion Vehicle (ACV).

HOW DOES A HOVERCRAFT WORK? A Hovercraft is powered by a motor, which drives a fan. The bigger the vessel the bigger the motor and fan needed. The fan creates the thrust to drive the Hovercraft forward

HOW DOES A HOVERCRAFT WORK? Part of the fan thrust is ducted through the hull to lift the craft off the surface on a cushion of air. The air is held under the craft by a flexible skirt which keeps the air cushion pressure up.

HISTORY OF THE HOVERCRAFT The first recorded design for an air cushion vehicle was put forward by Swedish designer and philosopher, Emmanual Swedenborg in 1716.

HISTORY OF THE HOVERCRAFT The first hovercraft was built by Christopher Cockerell in 1956. SRN1

HISTORY OF THE HOVERCRAFT The theory behind the Hovercraft was originally tested in 1955 using an empty cat food tin inside a coffee tin, an industrial air blower and a pair of kitchen scales.

WHAT IS SO SPECIAL ABOUT A HOVERCRAFT? What makes a Hovercraft so unique is the fact that it can travel over any surface, as long as it is relatively smooth. EX: Water, Grass, Ice and Snow.

WHAT IS SO SPECIAL ABOUT HOVERCRAFTS? Hovercrafts can be used year round due to their unique design. They are used for: Sports Recreation Utility/Commercial Rescue Purposes

SPORTS / RECREATIONAL USES Cruising Hunting Fishing Touring

COMMERCIAL USES Hovercrafts are mainly used as icebreakers, ferrying crafts and hauling vehicles. Its primary use of commercial hovercrafts is hauling. It is sometimes used instead of barges or ocean line due to maneuverability and versatility

RESCUE USES The versatility of the Hovercraft allows it to be used in most rescue operations Flooded areas, mud, ice, sandbars, swamps and other dangerous surfaces Hoverguard 1000 Hoverguard 700

ANY QUESTIONS?