How It Works
Skyships are equipped with a pair of ballonets, one forward and one aft. These ballonets are air-filled compartments within an airship that compensate for the expansion and contraction of the helium, thereby maintaining a required envelope pressure. They can be filled, or partially filled, with air. Emptying of air is done through four valves under the envelope. The valves open automatically as the ship climbs, releasing air and allowing the ballonets to collapse and the helium to expand. On descent, internal trunking allows air to be driven in from the propeller ducts, and / or electric fans, and thus avoid collapse of the envelope. The ballonets can be independently filled by using shut-off dampers in the air supply trunking. One important by-product of ballonet operation is that through differential inflation a measure of pitch trim can be obtained, in much the same way as a submarine uses its water ballast for buoyancy trim.
Read more about this topic: Airship Industries Skyship 600
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