Physics & Principle of Balloon Flight
The “Magical” Sky Experience
Some Interesting Air Conditions.
» WIND SHEAR
Wind shear occurs when the upper air current flows in an opposing direction to the lower air current. A balloon passing through the region of change between the two opposing wind flows is called "wind shear." Once through this region, the balloon will travel in the reverse direction.
» THERMAL ACTIVITY
Thermal activity is a rising of warm air which can become apparent as the day warms up. This is one of the main reasons why flights are taken in the early hours of the morning around day break when the air is cool and calm. Thermals are good for gliders but not for balloons. Daytime flights can be done during the 3-4 months of winter, when the air is still, calm and cool.
» FALSE LIFT
False lift is a horizontal flow of air over the crown of the balloon, assisting in the lift of the balloon system. It is also the reason for the upper surface of aircraft wings being curved to assist the lifting process. You can see exactly the same affect that when the rounded back part of a spoon is held freely against the vertical flow of water from out of a tap, the spoon is pulled into the flow of water.
Try it with a spoon!
» CORIOLIS FORCE
Named in 1835 after the French engineer and mathematician Gustare Gaspard Coriolis, the Coriolis force describes the effect of motion on a rotating body and its fundamental importance to meteorology, ballistics, and oceanography. In this case it is the revolving of the planet earth which determines the general wind directions, and is responsible for the rotation of cyclones, anticyclones, hurricanes and tornadoes.
In the Southern Hemisphere, an anticyclone represented by H (high pressure) revolves anticlockwise and the cyclone L (low pressure) revolves clockwise. In the Northern Hemisphere, it is the reverse of these directions. The Coriolis force can be witnessed in your own home. In the Southern Hemisphere the water passing down the plug hole of a sink or basin revolves anticlockwise, while it rotates clockwise in the Northern Hemisphere.
