FREE CONVECTION EFFECTS ON THE UNSTEADY LAMINAR BOUNDARY-LAYER FLOW PAST A POROUS LIMITING SURFACE WITH UNIFORM SUCTION IN STELLAR ATMOSPHERES

Unsteady two-dimensional free convection flow of a viscous fluid (e.g., of a stellar atmosphere) past a porous limiting surface (e.g., of a star) through which suction with uniform velocity occurs is considered when the free-stream velocity and the temperature of the limiting surface are arbitrary functions of time. General solution of the equations governing the flow is obtained in closed form with the help of two-sided Laplace transform technique under the assumption that there exists a mean steady flow to which is superimposed the unsteady flow. Further, in order to demonstrate the applications of the results of the general theory, four particular cases have been considered by prescribing physically acceptable different time-dependent forms to the temperature of the limiting surface and to the free-stream velocity. The results thus obtained for these four cases are discussed quantitatively. © 1979 D. Reidel Publishing Co.