Originally posted by Alaskan Man
that last clip is almost unreal, what causes that halo effect around the jet, pretty neat.
Originally posted by OldDragger
reply to post by OneNationUnder
It's NOT from going supersonic! It's called The Prandtl-Glauert Singularity.
Read and learn!
Wiki Prandtl singularity
[edit on 2-4-2010 by OldDragger]
The Prandtl–Glauert singularity or P.G. singularity is sometimes referred to as a vapor cone, shock collar, or shock egg.
The point at which a sudden drop in air pressure occurs is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft traveling at transonic speeds.
Transonic is an aeronautics term referring to the condition in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil. Air flow velocities are concurrently below, at, and above the speed of sound at the pressure and temperature of the airflow of the air vehicle's local environment (about mach 0.8–1.2). It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow over an air vehicle or air foil are supersonic, and a higher speed, typically near Mach 1.2, when all of the airflow is supersonic. Between these speeds some of the airflow is supersonic, and some is not.