Discrete values of the large scale structure in turbulent flows

Abstract

The time average of the amplitude of a single intermittency signal in a free jet was measured. Two different methods of measurements were used: the instant integration of a single signal (intermittency detector and instant integrator) and the pattern recognition method based on the evaluation of a certain number of similar signals (sampling of an ensemble of digitized signals with a similar distribution of amplitude). The measurements, taken at random times and analysed by two different techniques show a special type of a distribution function. The distribution shows discrete values for different flow velocities and different nozzle diameters indicating the existence of eigenvalues in the flow.