The provided diagram illustrates the structural components of a hot air balloon and explains the underlying physical principles that allow it to operate. The system relies on a combination of specific hardware and the density difference between heated and ambient air.
Structurally, the balloon consists of an envelope, which is the main body, constructed from panels and gores. At the top of this envelope is a parachute valve, described as a self-sealing flap designed to release hot air at a controlled rate. Below the envelope, a skirt connects to the burner and basket assembly. The burner is supplied by a propane cylinder, which provides the fuel necessary to heat the air inside the envelope.
Regarding the operational mechanism, the burner mixes propane with air to generate a flame. This process heats the air within the envelope, making it lighter than the surrounding cool air. This density differential creates the lift required for the balloon to ascend. Conversely, by manipulating the parachute valve to release hot air, the pilot can control the rate of descent. Overall, the balloon functions as a controlled thermodynamic system where fuel combustion regulates buoyancy.