A NUMERICAL STUDY OF THE THERMAL PERFORMANCE OF FINS WITH TIME-DEPENDENT BOUNDARY-CONDITIONS, INCLUDING INITIAL TRANSIENT EFFECTS

A finite-volume numerical model is constructed and applied to evaluate the time-dependent heat-transfer characteristics of longitudinal fins with a rectangular profile. To facilitate comparisons with analytical solutions, the problem is taken to be one-dimensional with constant t hermal properties. Two base boundary conditions are considered: (1) a step change and (2) a periodic change in temperature. Parametric studi es are carried out to investigate the effects of grid size, time step, fin parameter, Fourier number, amplitude and frequency of base-temper ature oscillation on the fin temperature distribution, heat-transfer r ate and efficiency. The study shows an excellent agreement between the numerical and analytical results and investigates the importance of t he initial transient effects.