论文部分内容阅读
针对大子午扩张变几何涡轮在可调静叶转动时旋转轴端严重恶化端区流场的问题,提出在可调静叶的机匣端部应用小翼结构的方法以克服这一问题并减少叶端间隙泄漏流动。应用数值方法和标准k-ω两方程湍流模型,并结合低速风洞试验,首先研究了可调静叶栅小翼端部流场及损失分布,并考虑了可调静叶转动的影响,随后给出了叶端凹槽状小翼结构,并评估了其气动性能以及对间隙变化的敏感性。研究结果表明:在可调静叶栅中应用叶端小翼不但可以避免可调静叶转动时旋转轴端恶化端区流场,还降低了叶端间隙泄漏驱动力,从而使得可调静叶在所有转角下都具有较好的端区流动性能,并且叶端小翼结合凹槽结构可以进一步减少间隙泄漏,总体上可调静叶栅总压损失系数降低了8.9%。
In order to overcome the problem of applying the winglets structure to the end of the adjustable stator vanes for the problem of serious deterioration of the flow field in the rotating shaft end during the rotation of the adjustable vane for the large meridional dwindling geometry turbine, Leaf tip gap leakage flow. By using the numerical method and the standard k-ω turbulence model and combining with the low-speed wind tunnel test, the flow field and the distribution of the tip of the adjustable vane casings are studied first, and the influence of the adjustable vane rotation is considered. The leaflet-shaped winglet structure is given and its aerodynamic performance and its sensitivity to the gap variation are evaluated. The results show that the application of the blade tip winglets in the adjustable stator blade cascade can not only avoid the flow field at the end of the rotating shaft end during the rotation of the adjustable stator blades, but also reduce the driving force of blade tip clearance leakage so that the adjustable stator blades In all corners have better end-zone flow performance, and the blade tip wing combined with the groove structure can further reduce the gap leakage, the overall adjustable stator blade total pressure loss coefficient decreased by 8.9%.