In this paper,small axial flow fan with struts is research object.Combined with the numerical simulation of flow field,effects of the number of struts,the diameter of strut and the tilt angle of strut on static characteristics,aerodynamic noise and internal flow field characteristics are analyzed.The response surface model that static pressure and noise are dependent variables when the number of struts,the diameter of strut and the tilt angle of strut are independent variables is established by response sur...