Vortices typically persist for between one and three minutes, with their survival likely to be longest in stable air conditions with low wind speeds. However, as the basic factor is weight, the vortex strength increases proportionately. The vortex characteristics of any given aircraft can also be changed by extension of flaps or other wing configuring devices as well as by change in speed. The strength of the vortex is governed by the weight, speed, and shape of the wing of the generating aircraft. After the roll up is completed, the wake consists of two counter-rotating cylindrical vortices.
This pressure differential triggers the roll up of the airflow aft of the wing resulting in swirling air masses trailing downstream of the wing tips. The lowest pressure occurs over the upper wing surface and the highest pressure under the wing. Lift is generated by the creation of a pressure differential over the wing surface. The origin of counter-rotating wing tip vortices is a direct and automatic consequence of the generation of lift by a wing. Jet Efflux and Prop Wash can also hazard the control of an aircraft both on the ground and in the air but, whilst these effects are often extreme, their effects are more short-lived. This type of turbulence is significant because wing tip vortices decay quite slowly and can produce a significant rotational influence on an aircraft encountering them for several minutes after they have been generated. Potentially hazardous turbulence in the wake of an aircraft in flight is principally caused by wing tip vortices. Where another aircraft encounters such turbulence, a Wake Vortex Encounter (WVE) is said to have occurred.
It will be generated from the point when the nose landing gear of an aircraft leaves the ground on take off and will cease to be generated when the nose landing gear touches the ground during landing. Wake Vortex Turbulence is defined as turbulence which is generated by the passage of an aircraft in flight.
0 kommentar(er)
