Correlations of scalars in homogeneous isotropic turbulence

The existence of a similarity law for the second-order two-point scalar correlation in the inertial-convective region of homogeneous isotropic turbulence where r is much less than l (the correlation width measure) is demonstrated by analogy to the second-order two-point velocity correlation found by Szablewski (1982), and the similarity law for the scalar spectrum in the region with wavenumber much greater than that of the large eddies (Szablewski, 1980) is used to derive integral relations permitting the approximation of the second-order scalar and third-order scalar-velocity two-point correlations. Numerical results are compared with published experimental measurements in graphs, and good agreement is obtained for the second-order scalar correlation but not for the third-order mixed correlation.