Shear Layer Transition and the Sharp-Edged Orifice

Abstract

The present experiments provide information about free shear layer transition to turbulence and the associated three-dimensional behavior patterns of vortex growth and breakdown. The free shear layers of a submerged jet were generated from two-dimensional sharp-edged orifices. Two distinct types of growth patterns, namely, the twisting growth pattern and the interlocking growth pattern were observed. The interaction phenomena of these vortex tubes are hypothesized to be associated with mutual induction. Quantitative data of exit central velocity, pre-coalescent wavelength between consecutive vortices, and vortex shedding frequency were measured and the interrelationships of Strouhal number, Reynolds number and the dimensionless convection velocity of vortices are discussed.