Flow and Heat Transfer Performance of Channels with ‎‎45 Degree Ribs in Staggered Array‎

Wang, Z.; Yin, Y.; Yang, L.; Yan, L.; Luan, Y.

doi:10.47176/jafm.14.05.32251

Flow and Heat Transfer Performance of Channels with ‎‎45 Degree Ribs in Staggered Array‎

Authors

¹ College of Power and Energy Engineering, Harbin Engineering University, Harbin, Heilongjiang ‎Province, 150001, China

² DIME – Department of Mechanical, Energy, Management and Transportation Engineering, University of Genoa, Via Montallegro 1, 16145 Genova, Italy

10.47176/jafm.14.05.32251

Abstract

The cooling efficiency of blade is growing demand with increasing turbine inlet temperature in gas ‎turbine development. Ribs used in cooling channels is a common cooling structure, therefore, many ‎configurations were studied by previous literatures, including angle, spacing, shape etc. However, there ‎are less research about the dislocation ribs structure. In this paper, the 45-deg parallel ribs, crossed ribs ‎and dislocation ribs were investigated by numerical simulation, in order to reveal the heat transfer ‎performance and flow mechanism. Refer to the experiment, SST k-ω model was applied in steady ‎simulation, at Re from 20000 to 50000. Due to the angled ribs can induce the secondary flow and ‎generate small helical vortices at front corner, heat transfer performance was elevated. The large rotating ‎vortices influenced by the ribs arrangement occupy the center channel, thence the dislocation caused ‎different flow and heat transfer results. The results shown that parallel rib has higher heat transfer ‎enhancement than crossed ribs, but pressure loss possess considerable level. At Re=21587, the averaged ‎turbulent kinetic energy of Case2.2 with dislocation ribs is 22.4% lower than parallel ribs. The all 45-deg ‎crossed ribs present higher level of overall thermal performance, and Case2.2 is optimal for the range of ‎Re investigated‎.

Keywords