CONVECTION DRIVEN BY THE NONUNIFORM ABSORPTION OF THERMAL RADIATION AT THE FREE SURFACE OF A STAGNANT POOL.
This is a study of the flow driven by the buoyancy effect associated with the nonuniform volumetric absorption of a spatially uniform flux of thermal radiation that impinges on a body of fluid. The nonuniform absorption of radiation is due to the presence of regions of relative turbidity (coloring, suspension of particulates, algae) that alter the optical properties of the fluid. Analytically, the phenomenon is investigated on the basis of scale analysis and an asymptotic solution that is valid for vanishingly small times or Grashof numbers. Numerical experiments performed in a shallow two-dimensional layer confirm the flow structure and scaling trends anticipated theoretically.