Image Measurements on ceiling mounted cooling systems
Image Helium extraction from natural gas
Image Solar Cooling
Image State of system and failure analyses
Image Thermostatic Expansion Valves
Image Prüflabor Wärmepumpen at ILK Dresden
Image Membrane-based Air Conditioning
Image Components for Cold Storage Systems
Image Thermal engines
Image Low noise and non metallic liquid-helium cryostat
Image Low temperature – test facilities
Image Test procedures for electrical components
Image Low Temperature Measuring Service
Image Calibration of Low Temperature Sensors
Image Cryostats, Non-Metallic and Metallic
Image Software modules

You are here:   /  Home


Reduction of primary noise sources of fans

BMWi INNO-KOM-Ost

01.04.2016 – 30.09.2018

Dr.-Ing. Ralph Krause

+49-351-4081-656

in Bearbeitung

ILK Projekt

...using numerical and experimental methods with contra-rotating axial fan

Focus of the research project

The project aims at the development of a low-noise contra-roating axial fan stage by conserving the high power density with respect to the acoustically demanding operating conditions. The noise reduction is achieved by a special design of the blades as well as braces with contact to the air flow. The potential of noise reduction is obtained by reducing

  • the specific sound power level and the improvement of
  • the psycho-acoustic parameters.

Reasons for noise sources

Sound sources can be characterised by the following figure according to Bommes (1994) and Carolus (2013).

Oppertunities of the blade design at axial fans.

Summary of noise source on fans (green: important noise sources at axial fans)

Pressure fluctuations due to transient forces at the blades are the main reasons for noise propagation. All further reasons (secondary sources, tertiary sources and stationary blade forces) are of minor importance or can not be influenced by fluiddynamical changes.

Noise Reduction

Due to the noise sources, different activities can be taken into account for reducing the noise propagation at fans. According to figure 2, following noise sources shall be in the focus of the research:

  • leading edge noise
  • trailing edge noise
  • instability waves
  • periodical separations
  • large scale separations
  • turbulent boundary layer
  • tip vortices

Outcome

The research project aims at the application of noise reducing activities of technical and psycho-acoustical manner with a contra-rotating fan by maintaining a constant high-level power density. The whole potential of noise reduction is estimated to be

  • 10 dB .
parameterstateaim (reduction)
specific sound power level43 dB-5...-7 dB
Psychoakustik no values -3...-5 dB (estimated)

Solution

The potential of noise reduction is divided into:

  • the reduction of the specific sound power level and
  • the improvement of the psycha-caoustics.

Throughout the research project, the following applications will be investigated:

  • serrations at the trailing edge a the first whell
  • sinusoidal structures at the leading edge of the second whell
  • porous structures at the first whell
  • serrations at the trailing edge of the first braces
  • sinusoidal structures at the leading edge of the second braces
  • porous elements in the shroud for reducing tip vortex noise 

Following techniques will be employed to obtain a solution:

Co-operation partners

You are interested? Get in contact with us.

Publications

Kercher M, Heimann J, Puhl C, Oeckel K, Friebe C and Krause R (2018), "Application of Rotational Beamforming Algorithms on fast Rotating Sound Sources", 7th Berlin Beamforming Conference 2018.

Kerscher M, Heilmann G, C.Puhle, Krause R and Friebe C (2017), "Sound Source Localization on a Fast Rotating Using Beamforming,the 46th International Congress and Exposition on Noise Control Engineering, Hong Kong, China", INTER-NOISE , HONG KONG. , pp. 626 (1-8).

Krause R, Friebe C, Kerscher M and Puhle C (2018), "INVESTIGATIONS ON NOISE SOURCES ON A CONTRA-ROTATING AXIAL FAN WITH DIFFERENT MODIFICATIONS", FAN 2018; International Conference on Fan Noise, Aerodynamcis, Applications and Systems, 18. – 20. 04. 2018, Darmstadt, Germany. , pp. 1-12.


Your Request

Further Projects

Image

Entwicklung eines schnellen Rechenverfahrens..

..für die Auslegung von Turbomaschinen basierend auf IBM

Image

Schalldämpfer mit integrierten Abgaswärmeübertrager

zur Verbesserung des Kaltstartverhaltens

Image

Aktives Schichtladesystem für Kaltwasserpufferspeicher

Temperaturgesteuerte Einschichtung von Kaltwasser mit unterschiedlichem Temperaturniveau


Contact

Institut für Luft- und Kältetechnik - Gemeinnützige Gesellschaft mbH
Bertolt-Brecht-Allee 20, 01309 Dresden


Secretary to the Management

+49-351-4081-520

+49-351-4081-525

Image ISO 9001
Bild Zuse Mitglied Bild SIG