Conclusions

1.) Spanwise variations in heat transfer enhancement of the dimpled rotating rectangular channel exist only for the twisted (J=135°) orientation.

2.) The dimpled channel behaves somewhat similarly to the ribbed channel. The dimpled channel however, does not dominate the rotational effects quite as significantly as in the ribbed channel. It appears that the dimpled channel promotes smaller scale, and more complex mixing vortices than the ribbed channel.

3.) The twisted (J=135°) dimpled channel experiences greater overall enhancement than the orthogonal dimpled channel (J =90°).

4.) For (J =90°), enhancement at the trailing surfaces increases by almost 100% from the stationary to highest rotation number case. Also, the leading surfaces show little dependence on rotation number. The side surfaces show slightly less dependence on rotation than those of a smooth duct.

5.) For (J=135°), enhancement at the trailing-outer surface increases by more than 100% from the stationary to highest rotation number case. In addition, the trailing inner and leading outer surfaces experience nearly identical enhancement, increasing by more than 50% from the stationary to highest rotation number case. The outer surface increases by nearly 100% and the inner surface slightly decreases from the stationary to highest rotation number case.

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