中文摘要：

针对45°叶型转折角扩压叶栅及增加小叶片后组成的大小叶片叶栅,分别测量了其在设计工况及不同气流攻角下的叶栅气动性能,通过PIV实验获得了对应工况下的叶栅内部流动状态.结果表明：增加小叶片后,叶片压力面至吸力面的压力梯度明显降低,大叶片载荷降低;在设计工况下,叶栅气流落后角仍可参考霍威尔半经验公式进行计算,但偏离设计工况后,该公式存在较大误差;大小叶片叶栅的气流落后角仅在小气流攻角下明显减小,在其余工况下变化不大;不同气流攻角下小叶片对大叶片表面气流流动分离起到约束作用;在设计工况至大气流攻角工况变化过程中,叶栅扩压损失有所降低.

英文摘要：

For diffuser cascade respectively with 45 degree turning angle and with splitter blades,aerodynamic performance of the cascade was measured under working conditions and at different attack angles,while flow structure inside the cascade studied under corresponding working conditions through PIV experiments.Results show that the pressure gradient from pressure surface to suction surface of large blade has been lowered substantially after small blade is added,and the load on large blade is reduced also; under design conditions,the lag angle of cascade flow can still be calculated according tO Howell semi-empirical formula,however,large error will be produced if the formula is used under off-design conditions; the lag angle of cascade with splitter blades shall be obviously reduced only in the case the attack angle is small,and under other conditions,little changes will be produced; the air flow separation on large-blade surface is restrained by small blade at different attack angles; the diffuser loss of cascade reduces in the process of changing the attack angle from design condition to large values.