  The paper is devoted to the study of natural convection and the formation of
delamination in an incompressible liquid due to convective laminar flows in a
closed region heated from the side. Weak, medium and intensive modes of
stationary laminar thermal, concentration and hemoconcentration (thermohaline)
convection are considered, in which nonlinear flow features are manifested that
can radically change the flow structure and characteristics of heat and mass
transfer. Nonmonotonic dependences of temperature and concentration segregation
in the center of the square region on the Grashof number (an intensity of flow)
were found. The features of the formation of a nonstationary periodic structure
of thermal convection in boundary layers and in the core of a convective flow
in a closed region are shown. Details of the formation of countercurrents
inside the region with the direction opposite to the main convective flow are
given. The influence of vertical and horizontal vibrations on oscillatory
convection is shown.
