改善二元亚音扩压器性能的试验研究

本文按文献1]提出的“失速裕度”设计法计算了二元亚音扩压器的几何尺寸和性能,其结果与作者所做的试验数据相差甚大.该扩压器是具有很大初始扩压角的突扩扩压器,在初始扩压段即出现严重的气流分离.此方法不适用的原因在于所用的附面层动量积分方程没有考虑壁面曲率项的影响.作者还对双扩压角直壁扩压器的性能进行试验研究,结果表明具有较大扩压角且短的初始扩压段的直壁扩压器性能优于相同面积比和长度的单扩压角直壁扩压器.此外,试验表明在分离点前安装适当型式和结构参数的叶片式涡流发生器能够控制扩压器内气流分离,从而使压力恢复系数C_p值提高25～34%.

EXPERIMANTAL INVESTIGATION ON IMPROVEMENT OF PERFORMANCE OF SUBSONIC TWO-DIMENSIONAL DIFFUSER

In this paper the calculation of the geometric dimension and the performance of subsonic two-dimensional diffuser is conducted according to the"stall margin"de-sign method presented in reference1].The result calculated is much different from the experimantal data presented by author.The diffuser adopted is a dump one with very large initial divergent angle.The severe flow separation is generated just initial divergent section.As the momentum integral equation of the boundary layer used in the method does not involve the effect of the wall curvature, es- pecially initial convex wall curvature, so that this method is not available to design the geometry of the diffuser for optimal performance. The experimantal results are presented to make a comparison between the pe- rformance of the two-dimensinal, straight wall diffuser with double divergent angles and that with single divergent angle. It is shown that at the same ratio of the diffuser exit to the inlet area and the same diffuser lenght, the static pressure recovery coefficient of the double divergent angles diffuser with larger initial divergent angle and shorter initial section is larger than that of the single divergent angle diffuser.In addition, the experimantal results also show that the flow separation in the diffuser can be controled due to a vortex generator with appropriate configuration and constructional parameters, located upstream to the separating point in the diffuser.Therefore the static pressure recovery coefficient of the diffuser is increased by 25%-34%.