Study of the flow field of an axial flow fan rotor subjected to circumferential inlet flow distortion and swirl

摘要

This paper outlines the combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan rotor at design and off-design flow conditions. Distortion is simulated by a perforated screen of 120° extent andswirl is effected through inlet guide vanes. Experiments are conducted at rotor inlet and rotor exit by using miniaturised pneumatic pressure probes. Measurements are obtained in the radial direction from the hub to the tip and in the circumferentialaxial velocities are presented in the form of contours and pitch averaged values. At design flow coefficient, swirl causes deterioration in the performance of the fan in addition to that caused by distortion. The attenuation of the defect appears to behigh in the presence of swirl.