亚声速压气机平面叶栅及其改型的吹风试验

Cascade testing for a subsonic compressor linear cascade and its modification

  • 摘要: 为了对比某压气机原始叶型及其改型后的短弦叶型的气动性能,基于某高亚声速叶栅风洞对原型和改型叶型开展了平面叶栅吹风试验。试验前对不带叶栅和带叶栅试验件下试验段进口均匀性和出口周期性进行检查,确定满足试验要求的测量通道。通过吹风试验测量并分析原型叶栅和改型叶栅的出口总压、出口气流角以及叶片表面等熵马赫数分布。结果表明:相对于原始叶型,弦长缩短后叶型吸力面型线曲率变化增大,峰值马赫数后的气流逆压梯度较大,因此附面层内的气流分离损失更大;设计马赫数0.6时,短弦叶栅的低损失攻角范围比原型叶栅减小了约3°,改型叶栅和原型叶栅均表现出较好的负攻角特性;设计攻角下(i=0°),进口马赫数从0.4增大至0.7时,两套叶栅出口尾迹的深度逐渐增大,但尾迹宽度基本不变;达到或者超过临界马赫数0.8之后,原型和改型叶栅的尾迹宽度和深度均显著增大。

     

    Abstract: In order to compare the aerodynamic performance of a compressor airfoil and its modification airfoil with short chord, the linear cascade tests for the baseline and modified airfoils were conducted in a high subsonic cascade wind tunnel. Before the formal experiment, the inflow uniformity and outflow periodicity were checked under the test condition with and without the test cascade, and the measurement blade passage was determined to meet the test requirement. By cascade experiments, the outlet total pressure, outlet flow angle, and the isentropic Mach number distribution on the baseline and modified cascades were obtained and analyzed. The experimental results show that the loss of the modified cascade is larger than that of the baseline, due to the larger adverse pressure gradient after the peak isentropic Mach number position caused by the larger curvature change of the modified cascade. At the design inlet Mach number 0.6, the incidence range with low total pressure loss of the modified cascade is three degrees larger than that of the baseline cascade, and both the baseline and the modified cascades show good loss characteristics under negative incidence condition. At the design incidence angle (i=0°), the wake profile depth of the baseline and modified cascades increases with the inlet Mach number 0.4~0.7. But when the inlet Mach number reaches the critical value of 0.8, both the depth and the width of the wake profile of the baseline and the modified cascades increase.

     

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