Experimental investigation on heat transfer characteristics of high blockage ribs channel

Abstract

The heat transfer and pressure loss characteristics on a square channel with two opposite surfaces roughened by high blockage ratio ribs are measured by systematic experiments. Reynolds number studied in the channel range from 1400 to 4500. The rib height(e) to hydraulic diameter(D) ratios are 0.2 and 0.33, respectively. The rib spacing(p) to height ratio(p/e) ranges from 5 to 15. The rib orientations in the opposite surfaces are symmetric and staggered arrangement. The experimental results show that (1) the heat transfer coefficients are increased with the increase of rib height and Reynolds number, though at the cost of higher pressure losses; (2)when the rib spacing to height ratio is 10, it keeps a highest heat transfer coefficient in three kinds of rib spacing to height ratio 5, 10 and 15; (3)the heat transfer coefficient of symmetric arrangement ribs is higher than the staggered arrangement ribs, but the pressure losses of symmetric arrangement ribs is larger than the staggered arrangement ribs.