The heat transfer characteristics of ribbed surfaces with rectangular channel were experimentally studied under different Reynolds numbers.The experimental results indicate that the small longitudinal ribbed surface of h=s=0.5 mm has great drag-reduction characteristics within the test range

and its drag-reduction declines with the increase of Reynolds number.As compared with heat flow in flat plate channel

the heat transfer characteristics of ribbed surface decreases in the case of 10 0001).Moreover

the heat transfer enhancement ratio increases with Reynolds number under test conditions.