The Effect of Elliptical Form of Cylinder on Free Convection in Annular Space

Abstract

We try through this research to present a detailed study on free convection heat transfer inside a closed space. The work is carried out in numerical way, using the method called finite volume. The governing equations are solved for numerical simulations of steady state and laminar regime. The studied domain is an annular space consisting mainly of two cylinders positioned horizontally, the inner cylinder has an elliptical shape with different aspect ratio (E) while the outer one has a single shape which is circular. The primary conditions adopted in this research are as follow: the outer cylinder has a cold surface, while the inner cylinder has a cold surface. The space between cylinders is considered to be filled with fluid of different values of thermo-physical proprieties (Pr). The fluid in the space moves under the influence of thermal buoyancy which is controlled by Ri number. The pertinent parameters for this research are: the aspect ratio of elliptical cylinder which is E = 0.1 to 1, the Prandtl number Pr = 1 to 100 and finally the Richardson number Ri = 103, 104 and 105. The results of this work show that the elliptical form allows an increase in thermal transfer activity. Also, values of the number Pr have a limited effect on heat transfer.