Low and heat transfer in a high-aspect-ratio rib-roughed cooling channel with longitudinal intersecting ribs
C. Zhang1, Z. Wang2, J. Kang3
1Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, Tianjin, China, 300384
2School of Energy and Power Engineering, Jinan, China, 250061
3School of Electrical and Electronic Engineering, Tianjin, China, 300384
Keywords: газовая турбина, внутреннее охлаждение, продольные ребра, увеличение теплопереноса, gas turbine, internal cooling, longitudinal intersecting ribs, heat transfer augmentation
Abstract
This paper describes a detailed numerical investigation of a stationary high-aspect-ratio rib-roughed rectangular cooling channel with longitudinal intersecting ribs near the gas turbine blade trailing edge region. In order to overcome the heat transfer performance degeneration in the high-aspect-ratio channel, longitudinal intersecting ribs are arranged on the channel bottom surface. The effect of the number of longitudinal intersecting ribs on the flow and heat transfer is systematically studied in the Reynolds number range Re=10000-30000. The results show that a heat transfer augmentation region exists just downstream the junction between the longitudinal rib and the angled rib due to additional secondary flows. With more longitudinal intersecting ribs, the heat transfer distributions on the channel surfaces are more uniform. Though the pressure loss is also enlarged with an increase in the number of longitudinal intersecting ribs, the overall thermal efficiency increases in the entire range of Reynolds numbers investigated. The configuration with two sets of longitudinal intersecting ribs shows the best overall thermal efficiency
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