SEMINAR ON HOVERCRAFT

Introduction A Hovercraft is a vehicle that  Flies like a plane but  Float like a boat  Drive like a car  It can hover over or move across land or water surfaces while being held off from the surfaces by a cushion of air.

 A Hovercraft can travel over all types of surfaces including grass, mud, muskeg, sand, quicksand, water and ice.Hovercraft prefer gentle terrain although they are capable of climbing slopes up to 20%, depending upon surface characteristics.

History  The first design by Swedish designer Emmanuel Swedenborg in  The project was short-lived because it was never built, for soon Swedenborg soon realized that to operate such a machine required a source of energy far greater than that could be supplied by single human equipment.  Until the early 20th century Hovercraft was not practically possible, because only the internal combustion engine had the very high power to weight ratio suitable for Hover flight.

SOME PICS OF HOVERCRAFT

T HE F IRST H OVERCRAFT  Christopher Cockerel thought of using a load of stuff you might find about the house to make a hovercraft.  Cockerel took a set of scales and a long rod and arranged them so the rod was vertical.  He then affixed a vacuum cleaner to the rod so it pointed down.  Next he made a hole in a can and affixed a can that was smaller than the first in such a way it allowed air in-between the two cans. Cockerel made the vacuum cleaner blow instead of suck, blowing air through the gap in the two cans, and it worked.  The scale went down as far as it could!.

B ASIC S TRUCTURE O F H OVERCRAFT Parts Of Hovercraft o Propeller :- It pushes the hovercraft ahead by pushing air behind. o Fan :- Primary purpose is to inflate the cushion contained within the skirt beneath the craft as well as to provide thrust with which to propel the craft forward. o Skirt :- Part that allows the hovercraft to clear obstacles. Generally speaking, the higher the skirt, the larger the obstacle that the craft will clear.

P RINCIPLE O F W ORKING  To lift the craft by a cushion of air to propel it using propellers.  The air sucked in through a port by large lifting fans which are fitted to the primary structure of the craft.  They are powered by gas turbine or diesel engine.

 Fan is used to inflate the skirt and rest is ducted down under the craft to fill area enclosed by the skirt.  At the point when the pressure equals the weight of the craft, the craft lifts up and air is escaped around the edges of the skirt.  So a constant feed of air is needed to lift the craft and compensate for the losses.

ADVANTAGES OF HOVERCRAFT Travel over any surface. Shortcutting routes. Travel rivers up as fast as down, irrespective of the current. Travel in dry water-beds. No collision with debris, logs etc. Access to 75% of coastal area instead of only 5% with conventional vessels.

Hovercraft are very fuel efficient (CO² friendly) as Hovercraft do not have to plough through the water but "fly" above the surface. At maximum speed fuel consumption of a Hovercraft is approx. 70% less than of a fast patrol boat with similar payload capacity. No turbulence or impact in water as no propeller churns up the water so sea life remains untouched

FUTURE OF HOVERCRAFT The future of hovercraft seems uncertain, but there is a good chance there will be huge hover ports all over the world, like the one in the picture. Thinner hovercraft might be built so civilians can drive safely on roads. It also seems likely that the larger hover vehicles will become larger than ever! Hovercraft are likely to be capable of high flight.

CONCLUSION Hovercrafts are generally simple mechanisms in theory. Yet the process from theory to manifestation is not as easy as it may seem. A plethora of problems exist and must be faced in order to attain a well functioning hovercraft. The plans and designs must be flawless. One must take under consideration the weight and the shape of each component in order to avoid problems such as instability and dysfunction. One thing is certain; when building a hovercraft, be well aware of the demands of construction. Be prepared and willing to embrace failure for it is the only way to success. Only after failed attempts will you be able to finally design an effective hovercraft.

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