Vortex dynamics behind cruising aircraft studied by a ground-based scanning lidar and airborne in-situ measurements

Ralf Sussmann; Horst Jaeger

doi:10.1117/12.275153

26 May 1997 Vortex dynamics behind cruising aircraft studied by a ground-based scanning lidar and airborne in-situ measurements

Ralf Sussmann, Horst Jaeger

Author Affiliations +

Proceedings Volume 3104, Lidar Atmospheric Monitoring; (1997) https://doi.org/10.1117/12.275153
Event: Environmental Sensing III, 1997, Munich, Germany

Abstract

By LIDAR and CCD camera analysis the geometrical evolution of a vortex phase contrail (descent rate V_d equals 2.7 m/s, vortex separation D equals 47 m, vertical extension (sigma) _z equals 140 m after 77 s) is analyzed. The contrail of a four-engine aircraft is showing a diffuse central wake phenomenon. From coincident in situ measurements all relevant meteorological parameters are characterized. Ambient humidity had been close to ice saturation. From this a non-exhaust formation of ice can be excluded. Also the mechanism of non- entrainment of exhaust into the vortices is excluded of being responsible for the observed early onset of the central wake (870 m behind aircraft). The central wake onset originates from early detrainment starting after a 3/4 roll-up period of the vortex. Baroclinic and shear forces do not contribute to the detrainment (imaginary Brunt-Vaisala-frequency N² equals negative 3 multiplied by 10^-5 s^-2, shear dS/dz equals negative 0.01 s^-1, bulk Richardson number R_i, equals N²/(dS/dz)² equals negative 0.3). Ambient turbulence had been fully developed with an inertial range and locally isotropic turbulence for wavenumbers k-equals 0.004 - 0.1 radian/m. The eddy dissipation rate (epsilon) equals 7.4 plus or minus 0.5 multiplied by 10^-5 m²s^-3 exceeds the values found over the North Atlantic flight corridor at cruising altitude by a factor of 1000. Turbulence was identified as the dominating detrainment mechanism.

Citation Download Citation

Ralf Sussmann and Horst Jaeger "Vortex dynamics behind cruising aircraft studied by a ground-based scanning lidar and airborne in-situ measurements", Proc. SPIE 3104, Lidar Atmospheric Monitoring, (26 May 1997); https://doi.org/10.1117/12.275153

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available