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

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.

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Surface Topography and Noise Emission in Gearboxes

Volume 1C: 16th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc97/vib-3790 ◽

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.

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

Fuel ◽

10.1016/j.fuel.2015.10.122 ◽

2016 ◽

Vol 166 ◽

pp. 392-399 ◽

Cited By ~ 40

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

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

AIAA Journal ◽

10.2514/1.j055513 ◽

2017 ◽

Vol 55 (5) ◽

pp. 1673-1680 ◽

Cited By ~ 1

Author(s):

M. J. Werner ◽

W. Würz ◽

E. Krämer

Keyword(s):

Experimental Investigation ◽

Noise Emission

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Numerical and experimental investigation of a beveled trailing-edge flow field and noise emission

Journal of Sound and Vibration ◽

10.1016/j.jsv.2016.08.005 ◽

2016 ◽

Vol 384 ◽

pp. 113-129 ◽

Cited By ~ 18

Author(s):

W.C.P. van der Velden ◽

S. Pröbsting ◽

A.H. van Zuijlen ◽

A.T. de Jong ◽

Y. Guan ◽

...

Keyword(s):

Experimental Investigation ◽

Flow Field ◽

Noise Emission ◽

Trailing Edge ◽

Beveled Trailing Edge ◽

Edge Flow

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A parametric study of airframe effects on the noise emission from installed contra-rotating open rotors

International Journal of Aeroacoustics ◽

10.1177/1475472x18789003 ◽

2018 ◽

Vol 17 (6-8) ◽

pp. 624-654 ◽

Cited By ~ 2

Author(s):

J Kennedy ◽

P Eret ◽

GJ Bennett

Keyword(s):

Experimental Investigation ◽

Wind Tunnel ◽

Parametric Study ◽

Emission Angle ◽

Flow Speed ◽

Scale Model ◽

Far Field ◽

Noise Emission ◽

Rotor Noise ◽

Open Rotor

This work reports on the results of the Clean Sky WENEMOR project which has conducted an extensive experimental investigation of installed contra-rotating open rotors on a scale model of an advanced regional aircraft configuration. The tests were conducted in the Pininfarina Wind Tunnel, Italy and the data used for this analysis were taken from a linear far-field array of microphones. The contra-rotating open rotors were operated in pusher and tractor modes with approach and takeoff settings for revolutions per minute and thrust. Realistic modern blade profiles were supplied and utilized through the Clean Sky Green Regional Aircraft program. A range of airframe geometries was tested which included interchangeable tails, engine pylon elongation, engine pylon rotation, and variable wing to engine distance. Changes in the contra-rotating open rotor noise emission to the far field as a function of flow speed, angle of attack, and airframe geometry were clearly identified. The influence of airframe geometry on contra-rotating open rotor tonal content, directivity, and broadband levels is reported for emission angles from [Formula: see text] to [Formula: see text]. Both significant noise increases and decreases with respect to the baseline airframe configurations were detected in both the tonal and broadband levels as a function of emission angle (ranging from 10 to 25 dB at the blade passing frequency tones). While the changes to the tonal level were generally greater than those of the broadband level, the broadband levels are shown to be significant when considering the influence of airframe geometries on contra-rotating open rotor noise emission.

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