Natural convection with variable viscosity and thermal conductivity from avertical wavy cone

The effect of variable viscosity and thermal conductivity on natural convec tion over an isothermal vertical wavy cone is studied in this paper. We con sider the boundary-layer regime having larger Grashof number and assume the wavy surfaces with O(1) amplitude and wavelength. Using the appropriate va riables the basic equations are transformed to nonsimilar boundary-layer eq uations which reduce the wavy cone to a fiat one. These equations are then solved numerically using a very efficient implicit finite-difference method known as Keller box scheme. Detailed results for the streamlines, isotherm s, reduced skin friction and heat transfer rates for a selection of paramet er sets consisting of the viscosity parameter, thermal conductivity paramet er, wavy surface amplitude and half cone angle. (C) 2001 Editions scientifi ques et medicales Elsevier SAS.