涡轮转子凹槽叶尖泄漏流动气动热力特征

Aero-Thermodynamic Characteristics of Tip Leakage Flow in Turbine Rotor with Squealer Tip

关键词:  涡轮  凹槽叶尖  泄漏流动  旋涡结构  流动换热  精细化组织

Key words:  Turbine  Squealer tip  Tip leakage flow  Vortex structure  Flow and heat transfer  Refine organization

摘要:

为探索总结凹槽叶尖泄漏流动气动热力特征，利用实验和数值模拟方法，对叶尖凹槽内部旋涡相互作用机理和叶顶流动换热与泄漏流能量再分布等问题进行研究，并对凹槽叶尖参数化设计方法进行探讨。结果表明：搭建的考虑多因素实验台和可视化泄漏流动测量方案可以精确地捕捉到叶顶区域的流动结构；刮削涡在凹槽中起到“气动篦齿”作用，其形态特征的变化直接影响凹槽叶尖对泄漏流动的控制效果；高温泄漏流流体对叶片表面的冲击是叶尖热负荷提高的主要原因；合理选择叶尖气动参数和凹槽的几何参数可以有效控制刮削涡形态，最终提升叶尖气动热力性能。

Abstract:

In order to explore and summarize the aero-thermodynamic characteristics of the tip leakage flow of squealer tip, experimental and numerical simulation methods are used to investigate the interaction mechanism of vortices in the squealer tip cavity, the tip region heat transfer and the energy redistribution of the leakage flow. The parametric design method of the squealer tip is also discussed. The results show that the multi-functional experimental platform and the visual leakage flow measurement scheme can precisely capture the flow structure in the tip region. An aero-labyrinth liked sealing effect is formed by the scraping vortex. Its shape characteristics directly affect the leakage flow controlling of squealer tip. The heat load increased in the squealer tip is mainly caused by the leakage flow impingement on the blade surface. By reasonable working condition and squealer tip geometry for organizing scraping vortex characteristics, the squealer tip can improve the turbine aero-thermodynamic performance effectively.