Quasistationary probability density functions in the turbulent mixing of a scalar field

Abstract
The assumption of the existence of an asymptotic shape when t→∞ for the probability density function (PDF) of an inert scalar field undergoing turbulent convection and molecular transport [Y. G. Sinai and V. Yakhot, Phys. Rev. Lett. 63, 1962 (1989)] is generalized to include the time evolution. Statistically quasistationary PDFs and conditional scalar dissipation rates compare surprisingly well with direct numerical simulation data at different times. Closed form PDFs are parametrized in terms of the flatness factor solely.