BUOYANCY INDUCED FLOWS ADJACENT TO HORIZONTAL SURFACES IN WATER NEAR ITS DENSITY EXTREMUM

Buoyancy induced flows generated in cold water adjacent to a horizontal surface are analyzed. A boundary region treatment is appropriate for a broad range of conditions when the net effect of the buoyancy force is away from the surface. This results in on-flow at a leading edge for a plane flow, which may arise when the spatial configuration of the buoyancy force may be described in two dimensional Cartesian coordinates. A radial or disk-flow results when the configuration is radially symmetric about a normal to the surface. The boundary-layer regime again results when the net buoyancy is away from the surface and flow is outward from the axis. Both kinds of thermally buoyant flows are considered in low temperature pure or saline water, wherein a density extremum may occur in the region of buoyancy. A new, very accurate and simple density equation yields a compact transport formulation for both plane and disk flows. Solutions are given for the Prandtl number and temperature conditions which normally occur. Buoyancy reversals and conditions for convective inversion arise. Detailed tabulations of transport parameters are included for both the isothermal and the uniform surface flux conditions. These results are compared with those arising when the conventional buoyancy force approximation is used. © 1979.