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摘要:
为明确跨音涡轮叶尖泄漏流动机理,进一步提升涡轮效率,对跨音条件下叶顶喷气对平叶尖及凹槽叶尖性能的影响进行研究,并探讨跨音条件下平叶尖及凹槽叶尖间隙内部的流动状态。结果表明:跨音条件下,叶顶喷气可以增加平叶尖叶栅的气动效率,而刮削涡仍是凹槽内的主控流动结构;喷气流量的增加对平叶尖的总泄漏流量影响有限,但会增加凹槽叶尖的总泄漏流量。在更高负荷情况下,平叶尖间隙内呈跨音速流动特征,具体状态与叶片负荷、叶片厚度有关;凹槽叶尖条件下,泄漏流动在吸力侧肋条上方快速膨胀至超声速状态。基于此,建立可用于跨音条件下的泄漏流量预测模型。
Abstract:In order to clarify the mechanism of the tip leakage flow in transonic turbines and further improve turbine efficiency, the effect of tip injection on the performance of a flat tip and a squealer tip is studied under the transonic condition, and the flow state in the clearance between a flat tip and squealer tip is discussed. The results show that under transonic conditions, tip jet can increase the aerodynamic efficiency of the flat tip cascade, and that the scraping vortex is still the dominant flow structure in the cavity of the squealer tip. The increase of jet flow has limited effect on the total leakage flow of the flat tip, but will increase the total leakage flow of the squealer tip. With higher load, the transonic flow in the flat tip clearance is related to the blade load and thickness. For squealer tips, the leakage flow expands rapidly to the supersonic state above the suction side squealer. Finally, a leakage flow prediction model for transonic conditions is established.
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Key words:
- transonic turbine /
- leakage flow /
- tip clearance /
- tip injection /
- flow model
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表 1 网格参数
Table 1. Grid parameters
网格编号 间隙径向网格数量 网格总数/106 网格1 9 2.51 网格2 15 2.67 网格3 21 2.84 网格4 26 2.98 网格5 31 3.14 -
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