捕获型线对内转式进气道外压段几何与气动特性的影响

以直内收缩锥流场为基准流场，构建了一套内转式进气道外压段的设计与性能快速分析程序.进而以矩形捕获型线为例，研究了决定捕获型线形状、位置的3个参数(中心距、旋转角和宽高比)对进气道外压段几何与气动特性的影响，将捕获型线为矩形、带圆角矩形及圆形时的外压段进行了对比.结果表明:捕获面平均半径是可作为评价外压缩段设计的一个重要几何参数，平均半径越大，总压恢复系数越高；对于矩形捕获型线而言，当中心距增加时，前缘长度、弧长、湿润面积单调增加，外收缩比单调减小，而旋转角和宽高比对外压段几何参数的影响比较复杂；在矩形捕获型线的3个参数中，中心距对总压恢复系数的影响最显著.此外，当捕获型线的中心距与面积保持不变时，圆角半径对外压段几何与性能参数影响不大. 

Effect of flow capture shape on the geometry and aerodynamic characteristics for inward turning inlet's external compression segment

Taking the constant slope internal cone flow as the basic flowfield, a program was constructed to design and quickly analyze the external compression segment performance of inward turning inlet (ITI). Then taking the rectangular capture shape for example, the effects of three outline and position determinant parameters, including center distance, rotation angle and aspect ratio, on the external compression segment''s geometry and aerodynamic characteristic were studied. At last, external compression segments with different flow capture shapes (FCS) (rectangular, rounded rectangular and circular) were compared. The results show that the average radius of flow capture shape can be used as an important geometric parameter to evaluate the total pressure recovery; as the average radius increases, the total pressure recovery goes higher. For rectangular capture shape, as the center distance increases, the length and arc length of external compression segment along with the wetted surface area increase monotonically, the external contraction ratio decreases monotonically, while the effect of the rotation angle and aspect ratio on the external compression segment is relatively complicated. Besides, among the three parameters, the center distance is the most sensitive parameter for total pressure recovery. In addition, if the center distance and capture area keep invariant, the fillet radius has little effect on the geometry and performance parameters of the external compression segment.