28-02-2013, 12:43 PM
AIRSHIP
AIRSHIP.ppt (Size: 622 KB / Downloads: 137)
Introduction
Airships or blimps are a type of lighter-than-air (LTA) craft
Use a gas to generate lift, like a hot air balloon
Move forward through the air under their own power, like airplanes
Hover like helicopters, travel in all kinds of weather and stay aloft for days
Inside an Airship
envelope - contains the helium gas
nose cone battens
forward ballonet
aft ballonet
catenary curtain
suspension cables
flight control surfaces - rudders, elevators
engines
air scoops
air valves
helium valve
gondola - holds passengers and crew
Envelope
Large bag that holds the helium gas
Cigar-shaped, for aerodynamic purposes
Made of a durable, airtight, lightweight fabric (polyester composites)
Can hold from 1,900 to 7,093 m3 of helium, depending upon the particular blimp
The pressure inside the envelope is low, approximately 0.005 ATM
Nose Cone Battens
Supports that radiate from the tip of the blimp
Stiffen the front of the blimp so that it is not damaged when it is moored to the mooring mast
Give the nose an aerodynamic shape, and prevent it from pushing in as the blimp travels forward
The mooring hooks are located in the nose of the blimp
Engines
The two engines provide the thrust necessary to move ahead
Turbo-propeller airplane engines that use gasoline fuel and are cooled by air
Generate several hundred horsepower, depending upon the particular blimp
Located on either side of the gondola
Blimps can cruise around 30 to 70 mph (48 to 113 kph)