Exploring effect of setting angle of exit strut on upper-stream pressure distortion

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.