Natural convection in a reservoir sidearm subject to solar radiation: A two-dimensional simulation

The natural convection in a reservoir sidearm subject to solar radiation is investigated numerically. It is revealed that the flow development from an isothermal and stationary state passes through three distinct stages, namely, air initial stage dominated by bottom heating due to the absorption of penetrative radiation there, a transitional stage characterized by the onset of convective instability in a form of rising plumes, and a quasi-steady stage evidenced by a quasi-steady large-scale circulation across the sidearm, which is maintained by a distinct horizontal temperature gradient. The numerical results agree qualitatively with those of a model experiment.