Entropy Cascade and Energy Inverse Transfer in Two-Dimensional Convective Turbulence

Two-dimensional system modeling a central region in an experimental box on the basis of the Boussinesq approximation is examined numerically. It is assumed that the effect of mixing and boundary layers on the central region is taken into account only as a forcing to the temperature dynamics. Neutrally stable stratification and homogeneity are also assumed. Entropy ($T^2$) spectra are compared with ones obtained by experiments. It is shown that smaller scales are governed by the entropy cascade process and large-scale modes are induced through the energy inverse transfer.