The small moving pieces on the rectifier blades are flow pieces. The flow vane is a pneumatic device used to improve the airflow direction and reduce airflow turbulence. It is usually installed in fluid power machinery, such as turbines, compressors, etc. The installation position of the flow vane is usually at the leading edge or trailing edge of the impeller. When rotating, the direction and speed of the airflow can be controlled, thereby improving the efficiency and performance of the machine. The tape-outs can be adjusted and replaced as needed to adapt to different working conditions and requirements. In the rectifier blades, the function of the flow vane is to control the flow direction and speed of the air flow, reduce the turbulence and loss of the air flow, and improve the efficiency and stability of the rectifier blades.