Numerical analysis of heat transfer and fluid flow in a three-dimensional wavy-fin and tube heat exchanger

The effects of different geometrical parameters, including tube row numbers (1-4 rows), wavy angles (theta = 8.95 degrees, 17.05 degrees, 32.21 degrees) and wavy heights (S = 0.751, 1.500 and 3.003 mm) are investigated in detail for the Reynolds number Re-H (based on the fin spacing and the frontal velocity) ranging from 400 to 1200. Numerical results indicate that the row effect is less important in a wavy-fin as compared to plain-fin counterpart. It is also found that, for equal wavy height, both the average Nusselt number and pressure coefficient are increased as the wavy angle is increased; while for equal wavy angle, they are decreased as the wavy height is increased. The combination of (theta = 8.95 degrees, S = 1.500 mm) gives the highest flow area goodness factor (j/f). A comparison of the numerical results with the available experimental data is also presented. (C) 1997 Elsevier Science Ltd.