[en] In this paper, investigation of viscous dissipation on heat transfer by supplying heat at upper portion of the vertical annular cylinder is carried out. The governing partial differential equations are non-dimensionalised and solved using finite element method. The inner surface of the cylinder is maintained at isothermal temperature and the outer surface at ambient temperature. The top, bottom and horizontal surfaces of the vertical annular cylinder are adiabatic. The effect of viscous dissipation for different values of Rayleigh number is discussed. (paper)