Numerical analysis of unsteady flow for stagger angle of stator cascade adjusting abnormally

In order to investigate effects on the airflow of cascade passage when the stagger angle adjusts abnormally, the flow field of cascade is predicted using NUMECA in different incidence angles when the stagger angle of some blade adjusts 5°. The flow field and the blade loads are analyzed when the stagger angle adjusting abnormally results in the cascade passage blocked. Results show that the flow becomes deteriorating and it shows the large scale boundary layer separation with the incidence angle increasing when incidence angle is positive. However, the flow is stable and the shedding frequency of vortex is up to 3500 Hz when incidence angle is negative. The incidence angle has an effect on the scale and shedding frequency of vortex when the stagger angle adjusts abnormally. Moreover, the fluctuation of aerodynamic force increases rapidly with incidence angle increasing when the incidence angle is positive.