【摘要】 对具有大转角的常规直叶片、正弯与反弯叶片的三套大尺寸、低展弦比的矩形叶栅进行了低速风洞实验,详细测量了栅前三个、栅内六个和栅后一个轴向垂直面内的气动参数.实验结果表明,与常规直叶片相比,叶片的反弯曲削弱了马蹄涡和通道涡的强度,并抑制通道涡向叶栅中部发展,从而避免了上、下通道涡的汇合.因此,反弯叶片叶栅中的二次旋涡损失显著降低,流动特性大为改善.更多还原

【Abstract】 The experiments in a low-speed plane cascade wind tunnel were carried out for three large scale rectangular cascades of small aspect ratio with conventional straight blades, positively and negatively curved blades. The aerodynamic parameters at the measurement planes arranged as 3 before, 6 in and 1 after, the cascades were measured in detail. The experimental results show that blade negatively curving weakens the intensities of the horeshoe vortices and passage vortices, and controlls the developments of passage vortices to the midspan, as a result avoids the meeting of upper and lower passage vortices. Thereby, the secondary vortex losses in the cascade with negatively curved blades are obviously reduced, the aerodynamic characteristics are considerably improved, compared with those in conventional straight cascade.更多还原