Higher‐Order Correlations in a Turbulent Field

TLDR: In this article, higher-order time-correlations and the associated skewnesses and flatness were measured in a turbulent field downstream of a grid using high-speed computing techniques and the results were obtained using samples of 160 020 digitized data recorded at time intervals of 1/12 800 sec during time periods of approximately 12.5 sec.

Abstract: Higher‐order time‐correlations and the associated skewnesses and flatnesses were measured in a turbulent field downstream of a grid using high‐speed computing techniques. The results were obtained using samples of 160 020 digitized data recorded at time intervals of 1/12 800 sec during time periods of approximately 12.5 sec. Comparison is made between the measured correlations and the higher‐order correlation curves corresponding to a Gaussian probability density distribution of turbulent velocities. The departures from Gaussianity are shown, and non‐Gaussian probability distributions are proposed which correspond considerably better to experimental reality. Several relations between correlation coefficients of different orders are obtained for the non‐Gaussian probability distributions and confirmed by comparison with the measured correlations, skewnesses, and flatnesses.