Accession Number : ADA017586

Title :   Investigation of Vortex Wake Stability Near the Ground.

Descriptive Note : Final rept. 1 Feb 74-31 Mar 75,

Corporate Author : AEROVIRONMENT INC PASADENA CALIF

Personal Author(s) : Tombach,I. H. ; Crow,S. C. ; Bate,E. R. , Jr

Report Date : 31 JUL 1975

Pagination or Media Count : 75

Abstract : Vortex wakes exist in a complicated environment near the ground at airports. Under many situations, factors combine to move a wake sufficiently far from the runway approach corridor that it does not constitute a hazard to following aircraft. Situations exist, however, where a wake can possibly linger at high strength long enough to present operational problems. The sinuous mutual induction instability of a vortex pair has been investigated theoretically and experimentally in atmospheric conditions which prevail near the ground, thereby extending previous work of Crow and Bate for the same instability aloft. Two theoretical models were developed -- one for a vortex pair in the constant stress layer of the atmospheric boundary layer, and the second for a vortex interacting with its image when in ground effect.

Descriptors :   *Wake, *Airports, *Vortices, Aviation safety, Instability, Mathematical models, Time, Experimental data, Ground level, Atmospheric circulation, Boundary layer

Subject Categories : Terminal Flight Facilities
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE