An Experimental Hydrodynamic Investigation of the Inception of Vortex Ventilation

Results are presented from a hydrodynamic investigation of the inception of vortex ventilation on modified-flat-plate rectangular lifting surfaces of aspect ratio 0.25 differing in scale and thickness ratio. Two types of bubble-formation processes are described. Inception speeds were correlated for bubble formation in the high angle-of-attack range by using the Froude number and for that in the low angle-of-attack range by expressing the speed as a function of the thickness ratio.