Affiliations: Mitsuba Corporation, 598, Minegishi, No, Niisato,
Seta, Gunma, 376-0122, Japan | Department of Mechanical and Production Engineering
Niigata University, 8050 Ikarashi 2, Niigata, 950-2181, Japan | Mitsuba Corporation, 1-2681, Hirosawa, Kiryu, Gunma,
376-8555, Japan
Abstract: The aerodynamic noise and the wake flow field in a cooling fan under
actual operating conditions are studied with and without winglets on the fan
blades. In order to understand the influence of the winglet, the aerodynamic
noise and the wake velocity distribution are measured. The results indicated
that overall noise level decreased and the noise spectrum was changed in a low
frequency range when the winglet was installed. It was found from the flow
visualization and PIV measurement that the influence of the winglet appeared in
the traces of the tip vortices and the magnitude of vorticity was reduced in
the near wake region, which suggest the observed reduction in aerodynamic
noise.
Keywords: Aerodynamic noise, Flow visualization, PIV, Fan, Winglet, Tip vortex
