Abstract To investigate the effects of tip gap height and the squealer cavity depth on aerothermal performance of a gas turbine rotor, two tip gap height and eight squealer cavity depth are investigated under stage environment. For the aerodynamic performance of blade tips, when the tip gap height is increased from 1.0% span to 1.5% span, the tip leakage flow rate is increased by about 1.0% total mass flow and the total pressure loss coefficient is increased by about 0.03. With the increase of cavity depth, the tip leakage flow rate is reduced but the vortexes loss in the cavity and passage vortex is enlarged, so the total pressure loss coefficient is reduced at first and then is increased. For the film cooling effectiveness of blade tips, the average film cooling effectiveness of tip is improved at a large tip gap height and a small cavity depth. With the increase of cavity depth, the area needed cooling protection is increased; the relative location between the film hole and the separation line is changed, resulting in the change of film area of the squealer tip. Thus, the film cooling effectiveness of the squealer tip is reduced with fluctuation when the cavity depth is increased. In all, the influence of the tip gap height and cavity depth on tip leakage flow rate, total pressure loss coefficient and film cooling effectiveness is conflicting. Determining an optimal cavity depth in which more film holes located on the separation line for a fixed tip gap height is important to obtain better aerodynamic performance and film cooling performance.

中文翻译：

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燃气轮机叶片叶尖间隙高度和空腔深度影响的气热分析

摘要 为研究叶尖间隙高度和静腔深度对燃气轮机转子气动热性能的影响，在级环境下研究了两个叶尖间隙高度和8个静腔深度。对于叶尖的气动性能，当叶尖间隙高度从1.0%跨度增加到1.5%跨度时，叶尖泄漏流量增加约1.0%总质量流量，总压力损失系数增加约0.03。随着腔深的增加，尖端泄漏流量减小，但腔内的涡流损失和通道涡流增大，因此总压力损失系数先减小后增大。对于叶尖的气膜冷却效率，在大叶尖间隙高度和小腔深的情况下，叶尖的平均气膜冷却效率得到提高。随着型腔深度的增加，需要冷却保护的面积增加；膜孔与分离线的相对位置发生变化，从而导致喇叭尖的膜面积发生变化。因此，当腔体深度增加时，汽轮机尖端的薄膜冷却效率随着波动而降低。总之，尖端间隙高度和腔深度对尖端泄漏流量、总压力损失系数和气膜冷却效率的影响是相互矛盾的。对于固定的尖端间隙高度，确定最佳腔深度，其中更多的薄膜孔位于分离线上，对于获得更好的空气动力学性能和薄膜冷却性能很重要。膜孔与分离线的相对位置发生变化，从而导致喇叭尖的膜面积发生变化。因此，当腔体深度增加时，汽轮机尖端的薄膜冷却效率随着波动而降低。总之，尖端间隙高度和腔深度对尖端泄漏流量、总压力损失系数和气膜冷却效率的影响是相互矛盾的。对于固定的尖端间隙高度，确定最佳腔深度，其中更多的薄膜孔位于分离线上，对于获得更好的空气动力学性能和薄膜冷却性能很重要。膜孔与分离线的相对位置发生变化，从而导致喇叭尖的膜面积发生变化。因此，当腔体深度增加时，汽轮机尖端的薄膜冷却效率随着波动而降低。总之，尖端间隙高度和腔深度对尖端泄漏流量、总压力损失系数和气膜冷却效率的影响是相互矛盾的。对于固定的尖端间隙高度，确定最佳腔深度，其中更多的薄膜孔位于分离线上，对于获得更好的空气动力学性能和薄膜冷却性能很重要。尖端间隙高度和腔深度对尖端泄漏流量、总压力损失系数和气膜冷却效率的影响是相互矛盾的。对于固定的尖端间隙高度，确定最佳腔深度，其中更多的薄膜孔位于分离线上，对于获得更好的空气动力学性能和薄膜冷却性能很重要。尖端间隙高度和腔深度对尖端泄漏流量、总压力损失系数和气膜冷却效率的影响是相互矛盾的。对于固定的尖端间隙高度，确定最佳腔深度，其中更多的薄膜孔位于分离线上，对于获得更好的空气动力学性能和薄膜冷却性能很重要。