Heat transfer study in a rotating ribbed two-pass channel with engine-similar cross section at high rotation number

The heat transfer in a rotating ribbed two-pass channel with engine-similar cross section has been experimentally investigated in the current study. The Reynolds number ranges from 10,000 to 50,000 for the inlet pass and 12,000 to 62,000 for outlet pass. The highest rotation number is 1.88 for the inlet pass and 0.972 for outlet pass. For channels, the leading and trailing sides are roughed with ribs (P/e = 9.8) placed at 90 degrees angle to the mainstream flow, and three channel orientations are considered (0 degrees, -22.5 degrees, and -45 degrees). Results show that placing ribs strengthen heat transfer for both stationary and rotating cases, and the ribs weaken the entrance effect. In the inlet pass, the most remarkable effect of Ro on Nu/Nu(s), is obtained on the trailing side, and a critical Ro is formed on leading and outer side. The heat transfer is enhanced by the rotation more severely at a larger Ro (Ro(1) > 1, Ro(2) > 0.5). Moreover, the beta = 0 degrees channel experiences the strongest heat transfer enhanced by rotation with the least in the beta = -45 degrees channel. At last, the average Nu/Nu(s) correlations considering Ro and Re are developed, a relatively pleasant accuracy (<= 10%) has achieved. (C) 2016 Elsevier Ltd. All rights reserved.