Scaling of mixed longitudinal velocity-temperature structure functions

Measurements in a turbulent round jet at a moderately high Taylor microscale Reynolds number $R_{\lambda}$ indicate that the mixed structure functions of u, the longitudinal velocity fluctuation, and θ, the temperature fluctuation, show a smaller departure from the Kolmogorov (1941)-Obukhov (1949) scaling than either the velocity or temperature structure functions at the same order. This reduced anomalous scaling indicates that the velocity and temperature increments are not statistically independent, as is reflected by the non-negligible correlation between velocity and temperature increments. The scaling exponents of both the temperature structure functions and the mixed u-θ structure functions increase with $R_{\lambda}$