低雷诺数下前缘形状耦合压力梯度调控附面层机理研究

Mechanism of Boundary Layer Control via the Superposition of Leading Edge Modification and Distribution of Pressure Gradients at a Low Reynolds Number

为深入了解低雷诺数下增压级正交叶片叶型表面的流动特性,发展高效的附面层调控策略,以高负荷增压级正交叶片某一截面处的叶型为研究对象,通过高精度参数化方法对该叶型进行改型设计。利用数值模拟手段,研究了低Re(Re=1.0×105)下层流分离及转捩对不同叶型的响应特性,阐明了前缘形状及叶片压力梯度对典型增压级叶型附面层发展的调控机制。结果表明:前缘压力尖峰和前加载压力梯度分布均能够有效抑制低Re下分离泡发展,消弱近壁区回流强度,将设计工况点叶型损失分别降低12.4%和12.5%,同时拓宽了低损失攻角范围;前缘压力尖峰耦合前加载压力梯度分布同时继承了上述优点,能够更大限度地提升低雷诺数下叶型的气动性能。相比于原始叶型,设计工况点叶型损失降低18.9%。该研究结果为低Re下增压级叶型的气动设计和流动调控提供有益借鉴。

This paper aims to provide a comprehensive understanding of the flow characteristics of the orthogonal blade surface of the booster stage at a low Reynolds number,as well as develop efficient strategies for boundary layer control.To this end,a blade profile extracted from a certain section of the orthogonal blades used in a high-load booster stage is modified using a high-precision parameterization method.Then,numerical simulation is conducted to compare the laminar separation and transition processes under various blade geometry conditions at Re=1.0×105.The mechanisms by which the growth of boundary layers can be controlled through the leading edge and distribution of pressure gradients are explained.The results show that both the spike near the leading edge and front-loaded pressure distribution can effectively suppress the growth of the laminar separation bubble at a low Reynolds number,thereby reducing the strength of reverse flow in the near-wall region.Compared to the baseline case,the profile loss is reduced by 12.4%and 12.5%,respectively.In addition,the incidence range of low flow losses is also extended.The superposition of the spike near the leading edge and front-loaded pressure distribution is found to be more effective in enhancing the aerodynamic performance of the blade,resulting in an 18.9%reduction in loss compared to the baseline case.These results provide valuable guidance for the design and flow control of blades in a booster stage operating at a low Reynolds number.