ASSESSMENT OF THERMAL PERFORMANCE OF FUNCTIONALLY GRADED MATERIALS IN LONGITUDINAL FINS

Assessment of the thermal characteristics of materials in heat exchangers with longitudinal fi ns is performed in the case where a conventional homogeneous material of a longitudinal fi n is replaced by a functionally graded one, in which the fin material properties, such as the conductivity, are assumed to be graded as linear and power-law functions along the normal axis from the fi n base to the fi n tip. The resulting equations are calculated under two (Dirichlet and Neumann) boundary conditions. The equations are solved by an approximate analytical method with the use of the mean value theorem. The results show that the inhomogeneity index of a functionally graded material plays an important role for the thermal energy characteristics in such heat exchangers. In addition, it is observed that the use of such a material in longitudinal fi ns enhances the rate of heat transfer between the fi n surface and surrounding fl uid. Hopefully, the results obtained in the study will arouse interest of designers in heat exchange industry.
   
Author:  R. Hassanzadeh and M. Bilgili
Keywords:  functionally graded material, heat transfer rate enhancement, inhomogeneity index, mean value theorem
Page:  79