Experimental investigation of the sound emission of skewed axial fans with leading-edge-serrations

Krömer F, Czwielong F, Becker S (2019)


Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2019

Event location: Delft NL

DOI: 10.2514/6.2019-2735

Abstract

Axial fans represent a major source of noise in technical systems. Based on investigations
on airfoils, a promising measure for reducing the sound emission of such systems with axial
fans is the application of leading-edge serrations to the fan blade. Hence in this study, the joint
impact of fan-blade skew – as a commonly used noise-reduction approach – and leading-edge
serrations on the sound emission of low-speed axial fans was investigated. Forward-, backwardand
unskewed fans with five different leading-edge modifications were used. For each fan, a
reference configuration with straight leading edges and four configurations with sinusoidal
leading-edge serrations (with two different amplitude values and two different wavelength
values) were examined.
The results show that among the reference fans with unmodified leading edges, the forwardskewed
fan had the lowest sound emission. The serrations applied to the unskewed fan lead to an
increase in the efficiency and a decrease in the sound emission. When applied in combination
with fan-blade skew, the serrated fans showed an even lower sound emission and a higher
efficiency – even the forward-skewed fan, which already has a low sound emission without
any leading-edge modifications. The highest sound reduction was achieved by applying the
serrations with the smallest wavelength and the highest amplitude. The findings prove that
even for low-noise fans with forward-skewed fan blades, a further sound reduction is possible
with the use of leading-edge serrations.

Authors with CRIS profile

Additional Organisation(s)

How to cite

APA:

Krömer, F., Czwielong, F., & Becker, S. (2019). Experimental investigation of the sound emission of skewed axial fans with leading-edge-serrations. In Proceedings of the 25th AIAA/CEAS Aeroacoustics Conference. Delft, NL.

MLA:

Krömer, Florian, Felix Czwielong, and Stefan Becker. "Experimental investigation of the sound emission of skewed axial fans with leading-edge-serrations." Proceedings of the 25th AIAA/CEAS Aeroacoustics Conference, Delft 2019.

BibTeX: Download