Partially wet fin efficiency for the longitudinal fins of rectangular, triangular, concave parabolic, and convex parabolic profiles

Abstract Fins are used in many extended heat exchangers. Occasionally, they are used in fully dry or fully wet surface conditions. However, if the dew point temperature is in the range of the fin base and fin tip temperatures, a partially wet surface condition is present. In this study, the partially wet fin efficiencies for the longitudinal fin of rectangular, triangular, concave parabolic, and convex parabolic profiles are presented. However, for each profile, there are two methods to derive the partially wet fin efficiency that depend on a set of boundary conditions. In addition, eight equations of fin efficiencies are investigated. According to the derivation, the fin efficiencies are the function of the length of the dry portion. Thus, the equations for calculating the length of the dry portion must also be presented. The results indicate that the fin with larger cross-section has a higher conduction heat transfer rate and more fin efficiency. Moreover, the partially wet fin efficiencies decrease with an increase in relative humidity. The equation for predicting the partially wet fin efficiency from fully wet and fully dry fin efficiencies is also presented.

[1]  D. Ganji.  The application of He's homotopy perturbation method to nonlinear equations arising in heat transfer , 2006 .

[2]  D. P. Sekulic,et al.  Extended surface heat transfer , 1972 .

[3]  Somchai Wongwises,et al.  Finite circular fin method for heat and mass transfer characteristics for plain fin-and-tube heat exchangers under fully and partially wet surface conditions , 2007 .

[4]  Goodarz Ahmadi,et al.  Analytical investigation on acceleration motion of a vertically falling spherical particle in incompressible Newtonian media , 2010 .

[5]  Balaram Kundu,et al.  An analytical prediction for performance and optimization of an annular fin assembly of trapezoidal profile under dehumidifying conditions , 2011 .

[6]  D. Ganji,et al.  Differential Transformation Method to determine fin efficiency of convective straight fins with temperature dependent thermal conductivity , 2009 .

[7]  Chi-Chuan Wang,et al.  Performance of Rectangular Fin in Wet Conditions: Visualization and Wet Fin Efficiency , 2001 .

[8]  L. Rosario,et al.  Analysis of heat transfer in a partially wet radial fin assembly during dehumidification , 1999 .

[9]  Davood Domiri Ganji,et al.  On unsteady rolling motion of spheres in inclined tubes filled with incompressible Newtonian fluids , 2011 .

[10]  S. Y. Liang,et al.  Comparison of one-dimensional and two-dimensional models for wet-surface fin efficiency of a plate-fin-tube heat exchanger , 2000 .

[11]  D. B. Kulkarni,et al.  Residue minimization technique to analyze the efficiency of convective straight fins having temperature-dependent thermal conductivity , 2009, Appl. Math. Comput..

[12]  J. W. Ramsey,et al.  Thermal Environmental Engineering , 1970 .

[13]  C. Arslanturk.  A decomposition method for fin efficiency of convective straight fins with temperature-dependent thermal conductivity , 2005 .

[14]  Davood Domiri Ganji,et al.  An analytical study on motion of a sphere rolling down an inclined plane submerged in a Newtonian fluid , 2010 .

[15]  A. Aziz,et al.  Thermal performance and efficiency of convective–radiative T-shaped fins with temperature dependent thermal conductivity, heat transfer coefficient and surface emissivity , 2012 .