UDС 536.25

M. Chandrasekar

VARIATIONAL APPROACH TO FREE CONVECTION BOUNDARY-LAYER FLOW WITH SUCTION AND INJECTION
The Gyarmati variational principle - a significant development in the field of the thermodynamics of irreversible processes - is employed to study suction and injection effects in flow and heat transfer in free convection boundary layer over a cone. The velocity and temperature distributions inside respective boundary layers are considered as simple polynomial functions, and with the use of the perturbation procedure the variational principle is formulated. The Euler-Lagrange equations are reduced to the coupled polynomial equations in terms of boundary-layer thicknesses. The skin-friction (shear-stress) and heat-transfer (Nusselt number) values with constant wall temperature are computed for various values of the suction and injection parameters and the cone angle parameter. The comparison of the present solution with an available numerical solution shows good agreement. Department of Mathematics, Anna University, Chennai 600 025, India; email: mchandru@annauniv.edu. Original article submitted May 24, 2006, revision submitted January 12, 2007.