001038 Binesh R;Balaji C (Heat Transfer and Thermal Power Laboratory, Department of Mechanical E, Indian Institute of Technology Engineering, Chennai-600 036) : Numerical simulation of heat transfer and entropy generation of convecting longitudinal fin systems. J Energy Heat Mass Transfer 2001, 23(3), 275-94.
A horizontal circular duct with external longitudinal fins, trapezoidal in cross-section, with turbulent flow inside is numerically analyzed, for heat transfer by convection and radiation, and entropy generation. The resulting two-dimensional fin equation is solved using a second order finite difference scheme for each of the fins in the system, together with formulation for radiation, to obtain the temperature distribution in the system. The analysis takes into account the variation of base temperature along the duct, traditionally ignored in most studies on such problems. The influence of geometric and thermal parameters, important from the design point of view, like thickness and height of the fin, number of fins, length and diameter of the duct is studied. In addition to heat loss per unit system mass, which is conventionally used to evaluate the performance of fin systems, the total rate of entropy generated by the system is also considered here. Keeping the entropy generation in the system to a low value can minimize total thermodynamic irreversibility of the system. A "hilistic" approach is used to consider simultaneously these two competing criteria; entropy generation and heat transfer to obtain an optimum design. Correlations are developed for entropy generation rate and heat loss per unit system mass, which will allow the generalization of the available data within the range of parameters considered.
9 illus, 2 tables, 14 ref
