Second law analysis of rectangular channels with square pin-fins

This paper presents heat transfer and friction characteristics, and the second law analysis of the convective heat transfer through a rectangular channel with square cross-sectional pin-fins attached over a flat surface. Various clearance ratios (C/H) and interfin distance ratios (Sx/D) were used, and optimum pin-fin arrays that minimize entropy generation were determined. It was found that Nu number based on the projected area decreased with increasing Sx/D and C/H, whereas Nu based on the total heat transfer area ıncreased wıth increasing Sx/D and with decreasing C/H. The friction factor was found to decrease with increasing Sx/D and C/H. Smaller entropy generation numbers were obtained at lower Reynolds number, higher clearance ratio, and hıgher interfin spacıng ratio.