ABSTRAKT

In this article, the rate of heat transfer from a curved vertical hot wall in a natural convection flow field was optimized by using the entropy generation minimization method. The continuity, momentum, and energy equations and equations of the second law of thermodynamics are solved iteratively by using the finite difference scheme. The length of the wall is divided into three parts. The curvature induced to the middle part and the curvature radii changed between 0 deg (flat plate) to 45 deg (half circle) in concave and convex shapes. Entropy generation, shear stress, Nusselt number and Bejan number distributions are computed along the wall. It is found in natural convection flow fields. The value of the Bejan number is approximately equal to unity, because of the small value of velocity in natural convection heat transfer; conduction heat transfer dissipation is dominant in entropy generation. The results show that in the convex case the value of entropy generation increases by increasing the curvature radii; but in the concave case the magnitude of entropy generation decreases to approximately 12 deg, after that this value increases.