Hovercrafts are vehicles that are designed to travel closely above ground or water. Hovercrafts are designed to achieve stability and high speed on water and on the ground by exerting a minimal amount of force. Construction of a hovercraft involves application various principles, theories and concepts. These are such as; air pressure, propulsion, friction and drag. This paper will discuss the basis theory in the operation of a hovercraft.Hovercrafts operate on the principles of lift and propulsion (Replica Hovercrafts, n.p). The lift principle is that which forces the hovercraft to raise few measures above the ground or water.
In order to lift a hovercraft off the ground, air must be directed under craft. Under the craft a skirt is usually present which traps the directed air creating pressure which forces the craft to move off the ground. The skirt is a flexible and inflatable barrier located to the bottom perimeter of the hovercraft (Basic Hovercraft theory, n.p). The skirt traps the air under the hovercraft as the fan continues to direct more air under. This eventually leads to the creation of pressure that is greater than the weight of the craft resulting in the lift. This airflow is normally generated by a fan. In order to maintain the stability of the hovercraft the right amount of air need to be directed under the craft.
Directing too much air will cause the craft to raise high above the ground causing it to tip over while too little air will not raise the craft resulting in little or no movement.The propulsion principle is that which makes the hovercraft to move above the ground (Replica Hovercrafts, n.p). The source of this propulsion force is also a fun which forces air backwards causing a thrust force which propels the craft in the fore direction. This fun, technically referred to as the thrust propeller, is usually an aircraft type having variable pitch blades.
They are usually located at the rare of the hovercrafts. To ensure stability of the craft the rotation of the thrust propeller must remain in tune to that of the engine and the lift fun. Since the craft is already suspended on air little force is required to propel it forward and the movement of the craft becomes easier.Another concept that is useful in the operation of a hovercraft is friction and drag. Friction force usually acts to reduce movement (Friction, n.p). Friction force is dependent on the type of surface on which the body is on and how hard the surfaces are pressed together.
Since hovercrafts are designed to move at high speed friction need to be reduced in order to archive this. The air cushion and the lifting process in hovercraft are usually created for this purpose. The air directed under the craft lifts the craft above the ground and act as lubricant enabling the craft to move faster with a smaller propelling force. Reducing friction also reduces greatly the amount of force required to propel the craft. Surface area is also an important concept in hovercraft (Farvis, n.p).
The surface area of the bottom of the hovercraft must be wide enough to enable the trapping of enough air that will increase pressure to the desired levels. Wider surface area also increases the stability of the hovercrafts.In summary, hovercrafts are vehicles designed to move while suspended closely above the ground or water. The main idea behind the hovercraft is to enable a large vehicles to move at great speed, while maintain stability and applying little amount of force. This idea in the hovercraft has been enabled through the application of the concepts of air pressure, propulsion, friction and drug.
Anonymous (2002). Basic Hovercraft Theory. Retrieved on March 26, 2011, from http://www.raymondclan.com/hover/theory.html#fn17
Anonymous (2000). Friction: Slowing Things Down. Retrieved on March 26, 2011, from http://www.darvill.clara.net/enforcemot/friction.htm
Anonymous (2005). Replica Hovercrafts. Retrieved on March 26, 2011, from http://www.quicktechhobby.com/Hovercrafts/what_are_hovercrafts.htm
Fravis (2009). Hovercraft and the Hovercraft Museum. Retrieved on March 26, 2011, from http://www.farvis.com/hoversrn4.htm