Numerical simulations for a single channel and muti-turn connected cooling channel model with 90°ribs is conducted to understand the effect of multi-turn connection on heat transfer and pressure coefficient of internal channel in rotor blade. The heat transfer of turned channel is measured by utilizing transient liquid crystal measurement
and the influence mechanism of multi-turn connection in tuning channel is revealed. Experimental results show that the velocity distribution is uneven in each passage due to tuning eddy. Both the pressure coefficient and the Nusset number(Nu)decrease along the flow direction. The Nu distribution is asymmetric in each passage due to turn-connection. The distribution of averaged Nu numbers has a multiple-peak form as a result of secondary flow induced by rib turbulations. The area of high Nu between two continuous ribs is gradually shifted to the rib downstream. The average Nu in each passage gradually increases while the ratio is slowly reduced as the Reynolds number increases.
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SU Guoguang, CHEN Hamnching, HAN Jechin. Computation of flow and heat transfer in two-pass rotating rectangular channels(AR=1:1, AR=1:2, AR=1:4)with 45-deg angled ribs by a Reynolds stress turbulence model[C]∥Proceedings of the 2004 ASME Turbo Expo. Norcross, GA, USA: American Society of Mechanical Engineers, 2004: 603-612.
HAN Jechin. Heat transfer and friction channels with two opposite rib-roughened walls[J]. ASME Journal of Heat Transfer, 1984, 106(4): 774-781.
FU Wenlung, WRIGHT L M, HAN Jechin. Heat transfer in two-pass rotating rectangular channels(AR=1:2 and AR=1:4)with 45 deg angled rib turbulators[J]. ASME Journal of Turbomacinery, 2005, 127(1): 164-174.
HUANG S C, LIU Y S. High rotation number effect on heat transfer in a leading edge cooling channel with three channel orientations[C]∥Proceedings of the 2012 ASME Turbo Expo. Norcross, GA, USA: American Society of Mechanical Engineers, 2012: 1289-1298.
KHALATOV A A, DAHEVSKYY Y Y, PYSMENNYI D M. Heat transfer and friction factor in the rib roughened blade leading edge cooling passage[C]∥Proceedings of the 2011 ASME Turbo Expo. Norcross, GA, USA: American Society of Mechanical Engineers, 2011: 1193-1203.
WRIGHT L M, GOHARDANI A S. Effect of coolant ejection in rectangular and trapezoidal trailing edge cooling passages[C]∥Proceedings of the 2008 ASME Turbo Expo. Norcross, GA, USA: American Society of Mechanical Engineers, 2008: 399-408.
SU Fubin, ZHU Huiren, GUO Tao, et al. Heat transfer enhancement within an internal passage by combinations of ribs and suction holes[J]. Journal of Aerospace Power, 2009, 24(7): 1500-1506.
CHEN Wei, KAN Rui, REN Jing, et al. Experimental investigation of heat transfer and pressure drop in a two-pass internal coolant passages of gas turbine airfoil[J]. Journal of Aerospace Power, 2010, 25(12): 2779-2786.
ZHU Jianqin, XU Guoqiang, TAO Zhi, et al. Numerical investigation of heat transfer and flow resistance in U-shaped variable cross-section channels with different rib heights[J]. Journal of Beijing University of Aeronautics and Astronautics, 2009, 18(1): 18-22.
ZHAO Shu, ZHU Huiren, GUO Tao, et al. Numerical predictions of flow and heat transfer for rotating internal cooling channels with rib turbulators[J]. Journal of Xi'an Jiaotong University, 2014, 48(2): 125-130.
YAN Y Y, OWEN J M. Uncertainties in transient heat transfer measurements with liquid crystal[J]. International Journal of Heat and Fluid Flow, 2002, 23(1): 29-35.