Author : S. V. Kadbhane and D. D. Palande

Steady state natural convective heat transfer from vertical rectangular fin array with isothermal and constant heat flux conditions is studied experimentally. Natural convective heat transfer from rectangular vertical fin array can be enhanced by optimizing the geometrical parameters such as fin length, width, height, and spacing. Also orientation of fin array, affects the natural convective heat transfer rate. An experimental set up was constructed to test 25 different fin arrays. Fin length and thickness were kept constant at L=200mm and t=2.5mm respectively. Fin spacing was varied from 5.5 to 14.5mm and height was varied from 5 to 25mm. Five different heat inputs ranging from 15W to 75W were supplied to all configurations. Experimentation revealed that optimization of geometrical parameters affects convective heat transfer rate. Effect of fin spacing on heat transfer rate was found more dominant than other geometrical parameters. It was observed that as fin spacing was increased, convective heat transfer rate also increases, reaches to maximum at a certain value of spacing known as optimum fin spacing and then decreases with further increase in spacing. Also it was observed that natural convective heat transfer rate is maximum for vertical orientation and it goes on decreasing as we incline fin array from vertical to horizontal.

Keywords: Natural convection, enhancement in heat transfer rate, geometrical parameters, angle of inclination, optimum fin spacing.