Inlet Gap Effect on Aerodynamics and Tonal Noise Generation of a Voluteless Centrifugal Fan
Journal article, 2022

In this paper, the gap effects on the aerodynamics and tonal noise generation of voluteless centrifugal fans are studied based on different gap geometries. The study is motivated by the state of the art of this type of fan, for which the tonal noise generation due to the gap turbulence has not been addressed concerning the gap geometry, while a recent study reported that there is tonal noise at the blade passing frequency (BPF) from the gap turbulence. We simulate the configurations using a hybrid method coupling the improved delayed detached eddy simulation (IDDES) with Formulation 1A of Farassat. Our simulation shows regions with high vorticity magnitudes in the channel between two blades near the trailing edges close to the shroud. The turbulence renders a uniform pressure rise. By changing the gap design, the turbulent regions can be reduced. The configurations show a similar trend of the root mean square (RMS) pressure on the blade leading edge (BLE), largest at the shroud, and decays when the distance to the gap increases. The gap designs affect the amplitude of the RMS pressure, which is connected to the BPF. Spectral analysis is performed for the surface pressure fluctuations and the sound pressure upstream of the fan. The surface pressure fluctuations show that, for all cases, the regions with high energy are identical to the locations where the gap turbulence evolves and accounts for the impingement on the BLE. The amplitude of the tonal noise at the BPF differs between the cases.

Computational aeroacoustics

Gap turbulence

Tonal noise

Voluteless centrifugal fan

Author

Martin Ottersten

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Huadong Yao

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Lars Davidson

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Journal of Sound and Vibration

0022-460X (ISSN) 1095-8568 (eISSN)

Vol. 540 117304

Reduction of noise from centriugal fans

Swegon, 2017-03-01 -- 2022-02-28.

Areas of Advance

Transport

Energy

Subject Categories

Applied Mechanics

Fluid Mechanics and Acoustics

Building Technologies

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1016/j.jsv.2022.117304

More information

Latest update

10/3/2022