Experimental investigation of the trailing vortex wake of a rectangular wing.
J. D. Jacob, D. Liepmann, and Ö. Savas
13th AIAA Applied Aerodynamics Conference,
1995, Paper No. 95-1841.
The trailing vortex wake behind an NACA 0012 rectangular airfoil is investigated in order to establish the general nature of both the near and far field wake for further experimental exploration of the stability characteristics. Preliminary results are presented. Measurements of the wake were made from 0 to 250 spans downstream of the airfoil with 20,000 < Re < 60,000. Velocity, vorticity, and circulation were resolved by digital particle image velocimetry (DPIV). It is found that the wake is extremely stable and long-lived. The motion of the vortex pair is fairly steady. The growth of the vortex core and corresponding circulation showed no appreciable decay over the measurement period. No short- or long-wave instabilities were observed in the naturally evolving vortex wake.