出口支板安装角对上游静叶流场畸变影响效应研究

Exploring Effect of Setting Angle of Exit Strut on Upper-Stream Pressure Distortion

以某增压级为研究对象,应用高精度无波动格式结合LU-SGS方法求解圆柱坐标系下N-S方程,获取出口支板不同安装角度时其流场细微结构,从支板安装角变化对上游流场压力畸变影响效应的角度,探索可靠高效的压气机出口支板/静子布局。数值结果表明:随着下游支板调节角度增大,增压级通流能力增强,其表面马赫数峰值提高且其位置后移,但上游进口段压力波动幅值减小,从而使得压力畸变减小,通过选择合理的支板安装角度可以有效降低上游流场压力畸变,改善流场结构。对于文中所研究的算例,可以适当增大支板安装角度以减小上游流场畸变,但最大不应超过5°。

Ref. 4 by Xiang et al and Ref. 5 by us achieved some success in reducing upper-stream pressure distortion through two different ways. Now our exploration has succeeded in obtaining a simple and effective method of selecting the setting angle of exit strut to reduce upper-stream pressure distortion. In the full paper, we explain our method in some detail; in this abstract, we just add some pertinent remarks to listing the two topics of explanation. The first topic is： the calculation method. In this topic, we explore the reasonable layout for the exit strut of a compressor stage relative to its upper stator. The second topic is. calculation results and their analysis. Its three subtopics are. the effect of setting angle on the Mach number distribution on the surface of the blade of an upper-stream stator （subtopic 2.1）, the effect of setting angle on the inlet pressure distortion of an upper-stream stator （subtopic 2.2） and the effect of setting angle on the inlet pressure distribution of an upper-stream stator （subtopic 2.3）. In subtopic 2.1, Fig. 3 shows the distribution of the Mach number at mid-span of the blade when the exit strut is placed at three typical setting angles. In subtopic 2.2, Fig. 4 indicates that the change of the setting angle of exit strut can effectively reduce the pressure distortion at different upper-stream axial locations. In subtopic 2.3, Figs. 5, 6 and 7 demonstrate that the exit strut at the down-stream has greater effect on the flow field at the upper stream than that of the stator itself on the upper stream. Therefore we conclude that the reasonable selection of the setting angle of exit strut can reduce the pressure distortion at the upper stream, improve the structure of the flow field and gain effective control of the flow field. The results in Fig. 3 show that the maximum setting angle should preferably not be more than 5 degrees.