DCCA cross-correlation analysis of 3D wind field signals in indoor and outdoor environments

Abstract

Uncovering dynamics characteristics of 3D wind field is of great importance to understand the mechanisms of gas dispersal and provides useful clues for the optimization of gas source localization algorithms. In this paper, we first use a high precision 3D ultrasonic anemometer to collect the three orthogonal wind speed components and calculate corresponding instantaneous wind speed. Then we employ the DCCA cross-correlation coefficient pdcca to quantitatively analyze cross-correlations between wind speed components, and between instantaneous wind speed and wind speed components in both indoor and outdoor environments. Our results suggest that the cross-correlations between wind speed components depend on time scales and exhibit different relationship in different environment. Moreover, we find that instantaneous wind speed shows a stronger positive level of cross-correlation with horizontal wind speed than that with vertical ones for both environments, indicating that the strength of instantaneous wind speed is mainly determined by horizontal wind speed. Finally, DCCA cross-correlation coefficients show that the 3D wind speed data of indoor and outdoor are influenced by identical seasonal components. These interesting findings yield novel insight into the inherent coupled flow behavior underlying a realistic 3D wind field.