Experimental investigation of the noise emission of axial fans under distorted inflow conditions

2016 ◽  
Vol 383 ◽  
pp. 124-145 ◽  
Author(s):  
Florian J. Zenger ◽  
Andreas Renz ◽  
Marcus Becher ◽  
Stefan Becker
Keyword(s):  
Experimental Investigation ◽  
Noise Emission ◽  
Axial Fans ◽  
Inflow Conditions

Aeroacoustic Optimization of a Pressure-Side Strut Configuration for Subsonic Axial Fans Using Statistical-Empirical Modelling

2018 ◽  
Author(s):  
Igor Neifach ◽  
Gi-Don Na ◽  
Frank Kameier ◽  
Nils Springer ◽  
Marco Wichers
Keyword(s):  
Residential Buildings ◽  
Statistical Design ◽  
Axial Fan ◽  
Noise Emission ◽  
Public Places ◽  
Empirical Modelling ◽  
Passive Construction ◽  
Cooling Fan ◽  
Rotor Stator Interaction ◽  
Axial Fans

This paper deals with the reduction of aerodynamically generated noise in passenger car Cooling-Fan-Modules (CFM), caused by the interaction between the impeller and the downstream-located strut configuration of the axial fan. Even after the car engine is switched off, the fan remains active, as long as cooling is required for certain vehicle components. Especially after a car has been parked in closed parking areas, in close proximity to residential buildings or public places, the noise emission can be a problem. This issue is addressed by dampening the rotor-stator-interaction through passive construction measures. In order to ensure optimal noise reduction, 8 critical design features of the struts are identified and investigated using statistical design of experiment methods (DoE). Based on the results, dedicated insights about the effects of concrete strut features on significant regions of the acoustic fan spectrum are obtained. Furthermore, an optimized strut configuration is derived and metrologically validated using a polyoptimization method. Compared to a current serial baseline configuration, a reduction of the overall sound pressure level by 2.6 dB(A), as well as a reduction of the blade passage frequency tone by 17.6 dB(A) is achieved.

Experimental Investigation of Noise Sources in a Needle Roller Bearing System

1999 ◽  
Author(s):  
Niccolò Baldanzini ◽  
Federico Beraldo ◽  
Monica Carfagni
Keyword(s):  
Experimental Investigation ◽  
Online Monitoring ◽  
Roller Bearing ◽  
Practical Method ◽  
Sound Power ◽  
Noise Emission ◽  
Noise Sources ◽  
Outer Race ◽  
Bearing System ◽  
Race Analysis

Abstract An experimental investigation was undertaken to determine the causes of noise emission scatter in hosiery machines. Following the experimental measurement of the sound power levels, the hosiery machine’s mechanical system was assembled and tested with components of various sizes. The results indicated that the source of the noise emissions was a bearing’s outer race. Analysis of the outer race’s roundness profile in relation to vibrations provided accurate predictions of machine behavior. On the basis of a correlation between noise and vibrations, a practical method of online monitoring was developed.

Surface Topography and Noise Emission in Gearboxes

1997 ◽  
Author(s):  
Naser Amini ◽  
B. G. Rosén
Keyword(s):  
Experimental Investigation ◽  
Total Energy ◽  
Surface Topography ◽  
Noise Generation ◽  
Test Rig ◽  
Noise Emission ◽  
Applied Torque ◽  
Surface Topographies ◽  
Before And After ◽  
Noise Assessment

Abstract This paper, by the experimental investigation, deals with the effect of different surface topographies on noise generation in gears. Results from the noise assessment of one gear before and after honing are discussed. The honing operation was applied to the gear after the grinding. The gear was tested in an actual gearbox, operated in a test rig. Running conditions were systematically changed during the test; however, the same conditions were utilized for the gear before and after honing. The aim of the study was to identify the mechanism of the expected noise reduction, with surfaces being evaluated in 3D. The following results have been obtained: The total energy in the noise decreases significantly. The magnitude of the tooth-mesh frequency dose not change, but the level of its higher harmonics decreases significantly. These reductions are especially significant, when running at higher rotational speeds or when the applied torque is increased.

scholarly journals Experimental investigation of a diesel engine power, torque and noise emission using water–diesel emulsions

Fuel ◽  
2016 ◽  
Vol 166 ◽  
pp. 392-399 ◽  
Author(s):  
Mohammad Reza Seifi ◽  
Seyed Reza Hassan-Beygi ◽  
Barat Ghobadian ◽  
Umberto Desideri ◽  
Marco Antonelli
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Noise Emission ◽  
Engine Power

Experimental Investigation of Tonal Self-Noise Emission of a Vehicle Side Mirror

AIAA Journal ◽  
2017 ◽  
Vol 55 (5) ◽  
pp. 1673-1680 ◽  
Author(s):  
M. J. Werner ◽  
W. Würz ◽  
E. Krämer
Keyword(s):  
Experimental Investigation ◽  
Noise Emission
Sign in / Sign up

Export Citation Format

Share Document