Correlation between Temperature and Velocity Fluctuations in the Near-Wall Region of Rotating Turbulent Channel Flow

The correlation between the temperature and streamwise velocity fluctuations in rotating turbulent channel flow is investigated. Unlike the previously found analogous property between the statistics of the temperature and streamwise velocity fluctuations, the correlation can more appropriately reveal the similarity between two random processes. The analysis of the correlation coefficient obtained from the database of direct numerical simulation indicates that the rotation weakens the correlation in most regions of the flow, especially on the suction side. Nevertheless, the correlation is slightly enhanced by the rotation in some regions of the rotating channel, which challenges the general understanding that rotation undoubtedly weakens the correlation. To discuss the mechanism of the rotating effect on the correlation, the transport equations of the variance of temperature and streamwise velocity fluctuations are considered. The Coriolis force is found to have an indirect effect on the correlation.