Transient free convection from an isothermal horizontal circular cylinder

A numerical solution of the unsteady free convection on an isothermal horizontal circular cylinder whose temperature is suddenly increased is presented at large Grashof number. Solutions for simultaneous development of the momentum and thermal boundary-layers are obtained by using the local non-similarity solutions method, together with the difference-differential procedure. The transient approach of velocity and thermal fields to the ultimate steady state and the variations in time of wall shear and heat transfer coefficients were found. The results at the lower stagnation point of the cylinder for Prandtl number Pr=1.0 are seen to improve the previous study of Hermann 1].