Velocity and Foldover of the Turbulent Non-Turbulent Interface in a Plane Jet.

摘要

A unique measure of the lateral component of the velocity of the turbulent-nonturbulent interface was defined and expressed in terms of the crossing frequency and intermittency, both parameters of the turbulent flow field. The velocity of the interface was compared for different turbulent shear flows and was found to show a trend of similarity. Experimental measurements of the velocity of the interface were taken in a two dimensional plane jet and found to correspond with the predicted values. Other characteristics of the interface were investigated and reported in this work. It was noted that the velocity of the front and back of the interface were not the same. A measure of the amount of folding in the interface as a function of location within the jet was also reported. It was found experimentally that the amount of folding increases directly with the intermittency. (Author)