Coherence of velocity fluctuations in a turbulent round jet

TL;DR

This study investigates the coherence of velocity fluctuations in a turbulent jet, revealing how coherence varies with flow parameters and regions, and demonstrating self-similarity in the flow structure.

Contribution

It provides new insights into how velocity fluctuation coherence depends on flow parameters and spatial regions in turbulent jets, highlighting self-similarity properties.

Findings

Coherence scales with system parameters.

Functional form of coherence varies by region.

Coherence exhibits self-similarity.

Abstract

Coherence between the velocity fluctuations measured at two points is investigated in a turbulent jet flow. Coherence is calculated in different regions of the flow by changing the separation between the points, the distance between the points from the exit of the jet and from its central axis, and the injection velocity of the jet. It is observed that coherence scales with the system parameters, the functional form of coherence and the corresponding scaling laws change depending on in which region coherence is measured, and that coherence is self similar in both the regions.