Friday, February 18, 2011

Hot Air Balloon by Lisa Dunleavy

Up, up, and away! Have you ever looked up into the sky and seen bright colors floating in the sky in the shape of a balloon? Then do you wonder how hot air balloons work? Hot air balloons were started by an array of scientists who worked off each other’s discoveries in the 1700s, and today it has turned into a fun leisure activity or a commercial advertisement.
There were two brothers who launched the discovery of hot air balloons, Joseph Michael and Jacques Etienne Montgolfier. In 1782, these brothers hadn’t been inventors, wanted to investigate why smoke rose. Furthermore, they wanted to know if smoke could life a person into the sky. Also, humans have always been intrigued by the thought of being able to fly like birds. The invention of the hot air balloon made flight in the air possible (First Hot Air Balloon).
Although, Joseph Michael and Jacques Etienne Montgolfier were the inventors of the hot air balloon, they couldn’t have done it without the help of Henry Cavendish. In 1766 Henry Cavendish was the first scientist that was able to isolate hydrogen. Hydrogen is the lightest gas, lighter than air. He then had the idea that it could be used to life things from the Earth because of its lightness. However, he didn’t further per sue his idea (Hot Air Balloon History).
Joseph Michael and Jacques Etienne Montgolfier lived in France and were paper makers. Their father wanted them to have a good education and sent them away to go to a private school. So they were educated, but after their education they continued to work on their paper mill. In 1782, they started their experiments to find if it really was possible to lift things from the Earth by using hydrogen gas said by Henry Cavendish. They filled a silk bag with hot air. The silk bag was less dense than the air, so it floated. Then the two brothers made their experiment a little bigger. Instead of using a small silk bag, they made a large bag that was shaped like a sphere. Then, they filled it with hot air from a fire and sent farm animals up in it. The farm animals were in a basket hanging below. After this success, they decided to send a human up in the hot air balloon. On November 21, 1783 they sent Pilatre De Rozier, a scientist, and Marquisd’Artandes on a hot air balloon flight in Paris. They were tied down for safety; however, they reached a height of 300 feet and stayed in the air for 20 minutes. Once the news of this success spread, the advancements on the hot air balloon spread rapidly. December 1, 1783 Jacques Charles and Moel Roberts lasted 27 minutes in the air in Paris as well, being the first officially in flight (in the other experiment, the balloon was tied down). Then, on June 4 in 1784, Elizabeth Thible became the first women to fly in a hot air balloon in Lyons, France.
What is a hot air balloon made of?
The major principle that makes the hot air balloon work is that hot air rises in cooler air. Why? The hot air rises because it is less dense. There are three main parts to a hot air balloon, the envelope, the basket, and the burner (How The Balloon Works).
The envelope, shown in figure 2, is the actually balloon part of the hot air balloon. Today it is made of nylon strips which are called gores. These gores go from the bottom of the envelope (balloon part) to the crown. The bottom two thirds is made of a combination or polyester and nylon this is similar to what a parachute would be made of. The envelope has to be woven extremely tightly in order to be air tight, keeping in the hot air which makes it float. Polyester and nylon are used because they are both lightweight and they are resistant to the high temperatures that are required for the balloon to rise. The bottom part of the envelope is called the skirt. The skirt is made of a material called Nomex. This different material is used because it’s extremely fire resistant (it’s the same material that fire fighters use) and the base of the envelope is what’s most exposed to the flames. The top one third of the envelope is made by the material hyperlast. Hyperlast is used because it is extremely strong. Also, it has a silicon coating on it to prevent mould or fungi build up. There are many different shapes, sizes, colors, and designs that envelopes come in.
The basket is another important part in hot air balloons as shown in figure 3. Without the basket there wouldn’t be any passengers or a conductor, and furthermore, there wouldn’t be a spot for the gas cylinders. Today, baskets are made of Kooboo and Palambang cane because of their lightweight, flexibility, and durability. It’s important to be flexible and durable for landing because when the hot air balloon lands, there is a lot of force exerted on it and the flexibility helps it absorb some of the pressure. Baskets come in many different shapes and sizes, but there are two main types of baskets, Open baskets and T-partition baskets. The open basket is completely open so that you could walk around on the whole thing as seen in figure 4.
Whereas the closed basket, as seen in figure 5, has different sections.
The last key component of the hot air balloon is the burner shown in figure 6. The burner is what allows the balloon to go in the air. The propane needed to heat the air is stored in cylinders in the balloon basket. The propane is stored in very compressed cylinders and is ignited by a pilot light. The flame burns and heats up the metal around it, heating the air. There are many different types of burners depending on the size of the hot air balloon and there can be quieter flames also.
Once you get up, how do you get down? First, you go up by opening the propane valve, which goes to the burner and lights a flame which then goes into the envelope. The more you open the valve, the more heat is released, so the rate of going up increases faster. Now, how do you get down? The parachute valve at the top of the balloon is a circle that has been cut out of the top of the balloon. Attached to the circle is a chord. The pilot just needs to pull the chord so the valve opens. This decreases the temperature bringing the hot air balloon closer to the ground (How the Balloon Works).
How is it used today?
The hot air balloon is used all over the world today. They are used for leisure activities, commercial flight, advertising for companies, sport, and weddings. You can go in a balloon ride for fun, for your wedding, or even to advertise your business. Hot air balloon has now even become a sport (How The Balloon Works)!
The hot air balloon was started by two brothers, who worked in a paper mill, Joseph Michael and Jacques Etienne Montgolfier (First Hot Air Balloon). Then, many scientists built off of their ideas. Today, their advances and trails have made a great impact on the world. Up, up, and away!
Journal Article: Hot Air Balloon Engine
This journal article talks about the balloon engine. It talks about how a balloon works and the math behind the engineering of the balloon. It discusses the ability to make an engine for a hot air balloon. The costs that it would have and also how it would impact the environment. It also talks about the heights that it could and the potential that it has (Hot Air Balloon Engine).
"How the Balloon Works." Web. .
"The First Hot Air Balloon." Web. .

"Hot Air Balloon History - Invention of the Hot Air Balloon." The Great Idea Finder - Celebrating the Spirit of Innovation. Web. 10 Feb. 2011. .

“Hot Air Balloon Engine.” Renewable Energy. Elsevier. Web. .

No comments:

Post a Comment