Noise from centriugal fans



Wall shear stress on a fan blade.


PhD student: Martin Ottersten
martin.ottersten@chalmers.se
Supervisors: Lars Davidson
lada@chalmers.se
Hua-Dong Yao
huadong@chalmers.se
Sponsors: Swegon
Publications: [1-3]
Start of project: March 2017
End of project: March 2022


BACKGROUND
Modern ventilation systems are often driven by isolated centrifugal fans which produce tonal and broadband noise. Exposure to tonal noise for a long-term can affect human bodies. It affects autonomous and hormonal systems in the body, which can lead to diseases such as high blood pressure, hearing loss and cardiac arrest. Also, mental disorders such as aggressiveness and mood swings [1][2]. The broadband noise can be decreased when the fan efficiency is optimized. However, the tonal noise is difficult to reduce.

The flow-induced interior noise for vehicles is mainly generated due to vibration of glass windows. The vibration can be excited by exterior turbulent flows that are developed from A-pillars and side-view mirrors as well as other accessories upstream of windows. It can also be excited by the exterior noise that is emitted from the turbulent flows. The research field on the flow-induced interior noise is aero-vibro-acoustics. However, as an innovative research filed, numerical and experimental tools and methodologies are not matured to date.

THE PROJECT

The aim of this project is to investigate the tonal noise from an isolated centrifugal fan, with unsteady RANS and Detached Eddy Simulation. We will develop a numerical method to predict and minimize fan tonal noise. The benefits are the energy saving in the ventilation system due to less pressure drop of silencers and healthier humans, because of the decrease of tonal noise.

A blog discussing practical issued can be found below


 

 

 

 
REFERENCES
  1. B. Berglund, T. Lindvall, and D. Schwela, “Guidelines for Community Noise”, in World Health Organization, (1999).  
  2. L Fritschi, L. Brown and R. Kim, “Burden of disease from environmental noise: Quantification of healthy life years lost in Europe”, in World Health Organization, (2011).  
  3. Martin Ottersten, Huadong Yao, Lars Davidson
    "Unsteady simulation of tonal noise from isolated centrifugal fan", FAN 2018 Darmstadt (Germany), 18 – 20 April 2018
    View PDF file
     
  4. Martin Ottersten
    "Numerical investigation of tonal noise sources from centrifugal fan", thesis of Lic. of Engng, Division of Fluid Dynamics, Dept. of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden, April 2020.
    View PDF file
     
  5. Martin Ottersten, Huadong Yao, Lars Davidson
    "Numerical and experimental study of tonal noise sources at the outlet of an isolated centrifugal fan", Report, Division of Fluid Dynamics, Dept. of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden, 2020.
    View PDF file
     


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