Purpose

The blade profile and its geometrical features play an important role in the separation of the boundary layer on the blade. Modifying the blade geometry, which might lead to the delay or elimination of the flow separation, can be considered as a passive flow control methodology. This study aims to find a novel and inexpensive way to reduce loss with appropriate modifications on the leading edge of the turbine blade.

Design/methodology/approach

Three types of wave leading edges were designed with different wavelengths and amplitudes. The selected numbers for the wave characteristics were based on the best results of previous studies. Models with appropriate and independent meshing have been simulated and studied by a commercial software. The distribution of the loss at different planes and mid-plane velocity vectors were shown. The mass flow average of loss at different incidence angles was calculated for the reference blade and modified ones for the sake of comparison.

Findings

The results show that in all three types of modified blades compared to the reference blade, the elimination of flow separation is observed and therefore the reduction of loss at the critical incidence angle of I = –15°. As the amplitude of the wave increased, the amount of loss growing up, while the increase in wavelength caused the loss to decrease.

Originality/value

The results of the present numerical analysis were validated by the laboratory results of the reference blade. The experimental study of modified blades can be used to quantify numerical solutions.

中文翻译：

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三种波前缘对工业涡轮叶片叶栅性能的影响

目的

叶片轮廓及其几何特征在叶片边界层的分离中起着重要作用。修改叶片的几何形状可能会导致流分离的延迟或消除，可以视为一种被动的流控制方法。这项研究旨在找到一种新颖且廉价的方法，通过对涡轮叶片前缘进行适当的修改来减少损失。

设计/方法/方法

设计了三种类型的波前缘，它们具有不同的波长和幅度。选择的波浪特征编号是基于先前研究的最佳结果。具有适当和独立网格的模型已通过商业软件进行了仿真和研究。显示了在不同平面和中平面速度矢量处的损耗分布。为便于比较，针对参考叶片和改进叶片计算了不同入射角下的损失质量流量平均值。

发现

结果表明，与参考叶片相比，在所有三种类型的改进叶片中均观察到流分离的消除，因此，在临界入射角I = –15°时，损失减小了。随着波幅的增加，损耗量增加，而波长的增加导致损耗减小。

创意/价值

本数值分析的结果已通过参考叶片的实验室结果得到验证。改进叶片的实验研究可用于量化数值解。