VARIATIONAL APPROACH TO FREE CONVECTION
BOUNDARY-LAYER FLOW WITH SUCTION AND INJECTION

M. Chandrasekar

UDC 536.25

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 a 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 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. Published in Inzhenerno-Fizicheskii 
Zhurnal, Vol. 80, No. 6, pp. 109-115, November-December, 2007. 
Original article submitted May 24, 2006, revision submitted January 
12, 2007.