Heat transfer characteristics in a rotating AR=4:1 channel with different channel orientations at high rotation numbers

Yang Li ^a,*, Jingwei Chen ^a, Wei Li ^a, Hongwu Deng ^b, Shulin Xue ^a

a. Hunan Key Laboratory of Turbomachinery on Small and Medium Aero-Engine, AECC Hunan Aviation Powerplant Research Institute, Zhuzhou, 412002, China
         b. National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing, 100191, China

Abstract: In order to reveal the effect of channel orientations on rotational heat transfer performance, this paper presents an experimental model of AR=4:1 smooth rectangular channel. The stationary and rotational heat transfer characteristics of the channel are studied in the range of Re=10000–40000 and Ro=0–1.23 under the channel orientation of 90° and 135°, which represent the basic one and realistic one, respectively. The experimental results indicate that for the trailing wall, the 90° channel shows a typical large range enhancement of rotational heat transfer, while the rotational effect becomes negative in most areas at 135° case. As the rotation number exceeds 0.7, the heat transfer of the trailing surface is greatly improved by rotational effect in 90° channel. When the channel was orientated at 135°, the leading surface heat transfer is more sensitive to rotation under the low rotation number (Ro<0 .3), and 20%–30% worse than non-rotating cases. the averaged nusselt ratios correlations under the channel orientation of 90° and 135° have been developed for further engineering applications.

Keywords: Turbine blade cooling; Rotational effect; Heat transfer correlations; High aspect ratio; Channel orientation