Quadrant analysis in the turbulent far-wake of a cylinder

The quadrant analysis technique of Willmarth and Lu (1972) has been used to estimate contributions from the four quadrants to the average momentum and heat transfers in the self-preserving region of a turbulent wake. The importance of sweeps near the wake centreline and of ejections at the edge of the wake becomes clearer when sweeps and ejections are viewed in the context of the topology of the large scale motion. The application of the quadrant analysis to the products of velocity and temperature fluctuations conditioned on the large scale motion, clarified the picture inferred from the conventional quadrant analysis approach by clearly identifying the regions of space which are important for transferring momentum and heat.