The principle of hot air balloon

The principle of hot air balloon is that it expands when heated and contracts when cooled.

After being heated, the air in the balloon of a hot air balloon becomes less dense and lighter than the cold air with the same volume outside the balloon, so the balloon generates buoyancy to lift off (like ice floating in water). When the burner heats the air in the balloon, the air in the balloon expands and the density becomes smaller, and the excess air after expansion is discharged from the bottom of the balloon. When the air temperature in the sphere drops, the buoyancy generated by the sphere is less than the weight and load of the sphere itself, and the balloon begins to descend. This is actually the principle of thermal expansion and cold contraction.

After the hot air balloon takes off, the fuel injection amount of the blowtorch is controlled to control the balloon to rise or fall. Hot air balloons first appeared, and now flying in hot air balloons has become a favorite air sports. In addition, hot air balloons are often used for aerial photography and air travel.

Hot air balloon flight instructions

1, time

The best time for hot air balloon flight is one or two hours after sunrise or before sunset in a day, because it is usually calm and the airflow is stable. Strong winds and fog are not conducive to the flight of hot air balloons. According to the regulations, only when the wind speed is less than 6m/s, the visibility is greater than 1.5km, and there is no precipitation in the flight airspace can you fly freely.

Step 2: Location

It needs a flat site of 30m× 30m, and there are no wires and tall buildings around. Freshmen are advised to fly in the climate of 4m/s, and pay attention to maintaining a safe height when flying over high-voltage lines, tall buildings, livestock farms and villages.

Step 3 equip

It is best to wear a one-piece cotton flight suit. Passengers are also advised to wear pure cotton clothes and hats in case of fire.

Step 4 take off

Flying a hot air balloon requires the joint efforts of a group of people, because the work of a hot air balloon on the ground is very complicated, and it takes at least four people for a hot air balloon to take off. Spread the balloon on the ground first, then connect it with the hanging basket put aside, and blow air into the balloon with a small blower to make it expand little by little. When it is fully unfolded, it will start to ignite. Light the fire and heat the air in the balloon. The hot air makes the balloon rise to a position perpendicular to the hanging basket. Add a few fires and the balloon will take off.

The above contents refer to Baidu Encyclopedia-Hot Air Balloon.