The influence of channel orientation on the local heat transfer coefficient in a rotating, U-shaped, square channel with smooth walls was investigated for rotation number from 0 to 0.26. The three channel orientations were square channel parallel to the rotation axis, square channel twisted at 22.5° to the rotation axis and square channel twisted at 45° to the rotation axis. A change in the channel orientation about the rotating frame causes a change in the secondary flow structure,consequently, the heat transfer coefficient from the individual surfaces of the channel changes. Results show that the Nusselt number difference between leading and trailing surfaces was reduced as the channel twisted to the rotation axis, however, the inner and outer surfaces show an increase in Nusselt number discrepancy over their corresponding parallel channel orientation values. Effect of channel orientation on heat transfer is relatively prominent for high rotation number.
Liu Chuankai, Tao Zhi, Ding Shuiting, Xu Guoqiang.Local heat transfer in a rotating U-shaped square channel with three channel orientations[J] JOURNAL OF BEIJING UNIVERSITY OF AERONAUTICS AND A, 2006,V32(03): 284-287
Yang W J, Zhang N, Chiou J. Local heat transfer in a rotating serpentine flow passage[J].ASME Journal of Heat Transfer.1992, 114:354-361
Han J C, Zhang Y M, Kalkuehler K. Uneven wall temperature effect on local heat transfer in a rotating two-pass square channel with smooth wall[J].ASME Journal of Heat Transfer.1993, 115:912-920
Cho H H, Kim Y Y, Kim K M, %et al%. Effect of rib arrangements and rotation speed on heat transfer in a two-pass duct . GT-2003-38609,2003
Parsons J A, Han J C, Zhang Y M. Effects of model orientation and wall heating condition on local heat transfer in a rotating two-pass square channel with 90° rib turbulators[J].International Journal of Heat and Mass Transfer.1995, 38:1151-1159
�˺���,�� ��,���ǿ,��. ��ת״̬����ת�Ǵ���U��ͨ���ڻ���ʵ���о�[J]. ��������ѧѧ��,2001,41(1):38~41 Deng Hongwu, Tao Zhi, Xu Guoqiang, %et al%. Experimental investigation on heat transfer within a rotating ribbed serpentine passage with stagger angles . Journal of Dalian University of Technology, 2001, 41(1):38~41(in Chinese)