叶片多尺度表面对压气机气动性能影响及其高性能制造研究进展

叶片几何形状误差精细化控制、表面波纹度控制和布置合理的介微观仿生减阻结构是提升压气机叶片气动性能的有效手段,也是目前新一代航空发动机重点关注的方向之一。这类结构通常几何形状复杂,制造难度较大。首先,综述了叶片几何形状误差、表面波纹度和介微观仿生减阻结构等不同尺度的表面特征对流场特性的改变以及不同尺度的表面结构特征对压气机气动性能的影响规律,分析了多尺度表面的制造工艺及其最新进展。其次,引出了气动性能约束下的压气机叶片高性能制造中对几何形状公差范围、表面波纹度以及介微观仿生结构制造技术的要求。最后,结合多尺度表面高性能制造发展现状,对进一步提升压气机叶片气动性能的研究内容与发展方向进行了展望。

An Outbreak of the SARS-CoV-2 Omicron Variant BA.1—Zhuhai City,Guangdong Province,China,January 13,2022

On January 13,2022,Zhuhai CDC received a notification that a coronavirus disease 2019(COVID-19)case was found in the fever clinic in nearby Zhongshan City.Zhuhai CDC promptly carried out large-scale population screening in three nearby counties.A total of 4 COVID-19 cases were found in Nanping County.34 cases were screened from close contacts,and 2 cases were reported from close contacts in other cities of Guangdong Province.The 20 cases were sequenced by Guangdong CDC and identified as the variant of concern(VOC)/Omicron variant BA.1.Since January 14,Zhuhai has carried out 8 rounds of nucleic acid screening for COVID-19 in the county where the cases occurred.Four large-scale nucleic acid screening tests for COVID-19 were conducted across the city,and no new community cases were reported after January 15.