For an optical system carried by a helicopter, aero-optic aberrations originate primarily from blade tip vortices that pass through the system field of view. These aberrations result from the reduced pressure and density in the vortex cores, and the associated variations in the index of refraction. As part of an investigation into the full aero-optic environment surrounding a helicopter, this paper describes an investigation into the optical character of a single tip vortex. The Lamb–Oseen vortex model is used to compute realistic velocity fields, which are then used with the energy equation to determine thermodynamic properties. The resulting aero-optic data are used to calibrate a scaling law that is derived from the basic fluid-mechanic equations of motion, and this scaling law is validated against experimental data. The scaling relationship is then used to make a simple estimate of the vortex-induced aberrations on a fuselage-mounted optical system for a medium-sized helicopter.
Aero-Optic Effects of a Wingtip Vortex
AIAA Journal ; 51 , 7 ; 1533-1541
2013-05-13
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
FLUID DYNAMICS - Aero-Optic Effects of a Wingtip Vortex
Online Contents | 2013
|NTRS | 1990
|NTIS | 1981
|NTIS | 1984
|Wingtip vortex dissipator for aircraft
NTRS | 1976
|