Aerodynamic and aeroacoustic properties of axial fan blades with slitted leading edges
Ocker C, Czwielong F, Chaitanya P, Pannert W, Becker S (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Book Volume: 6
Abstract
A detailed experimental analysis of the aerodynamic and aeroacoustic properties of flat-plate axial fans with slitted leading edges is performed. The sound emissions of five slitted leading edge designs are measured at a constant rotational speed and at a constant total-to-static pressure rise of the fans. For both cases, the fan blades with slitted leading edges reduce the turbulence interaction noise and lead to a reduction of the overall sound pressure level for volume flow rates above 0.6 m(3) s(-1) compared to an axial fan with solid leading edges. The far-field noise analysis shows that the slits result in a noise reduction for frequencies below 2 kHz and a noise increase above 2 kHz. In addition, sound source localization is conducted with a microphone array and rotating beamforming methods are applied. The identified sound source distributions prove that slitted leading edges reduce turbulence interaction noise, but generate broadband noise in the fan blades ' trailing edge regions. The maximum sound reduction due to the slits could be detected at a dimensionless frequency of fh/(w) over bar approximate to 0:5, where f is the frequency, h is the height of the slit and (w) over bar is the mean relative inflow velocity. The noise reduction mechanism on axial fan blades corresponds well to previous investigations on flat-plate airfoils with slits.
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Germany (DE)
United Kingdom (GB)How to cite
APA:
Ocker, C., Czwielong, F., Chaitanya, P., Pannert, W., & Becker, S. (2022). Aerodynamic and aeroacoustic properties of axial fan blades with slitted leading edges. Acta Acustica, 6. https://dx.doi.org/10.1051/aacus/2022043
MLA:
Ocker, Christof, et al. "Aerodynamic and aeroacoustic properties of axial fan blades with slitted leading edges." Acta Acustica 6 (2022).
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