Sound radiation by distributed quadrupole sources near rigid bodies

Ostrikov, N. N.

doi:10.1134/s1063771012040148

Cited by 2 publications

(1 citation statement)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reason for this is not clear, but it could be thought of as caused by a modification of spatial distribution of quadrupole sources in the turbulent wake behind the landing gear model due to installation of the wheels. It is known that spatial distribution of quadrupoles near a bluff body significantly influences noise produced by the bluff body [11] and thus may result to overall noise decrease despite the presence of the additional noise sources. This effect requires further investigation.…”

Section: Resultsmentioning

confidence: 99%

Experimental study of a noise reduction concept for realistic landing gear geometries

Belyaev¹,

Kopiev²,

Pankratov³

et al. 2014

20th AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

An experimental study of a noise-reduction concept for realistic small-scale (1:10) landing gears has been performed. The concept is based on the idea of the 'flat back' of a cylindrical leg and is realized as the truncated-cylinder form of the main leg of a landing gear, as well as a flat plate behind the main leg of a landing gear at several distances. It has been obtained that the concept does reduce overall noise of the realistic small-scale landing gear models by up to 2.4 dB. The effect of noise reduction has been observed for landing gears both with and without wheels. The effect has been found to persist in the presence of a small yaw angle. Thus, it is concluded that this noise-reduction technology is sufficiently robust and mature to be applied to large-scale models.

show abstract

Section: Resultsmentioning

confidence: 99%

Experimental study of a noise reduction concept for realistic landing gear geometries

Belyaev¹,

Kopiev²,

Pankratov³

et al. 2014

20th AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

show abstract

Study of Vortex Noise of Rotating Blades

Moshkov¹

2020

HoBMSTU.SNS

View full text Add to dashboard Cite

The paper gives a brief overview of propeller noise generation mechanisms. The vortex component of the propeller noise is considered in detail. The results of the study of the vortex noise of rotating rods in open areas are presented. The spectral, integral and spatial characteristics of the acoustic field of the rotating rods are obtained. We established that the audibility of rotating rods considered is determined by radiation in the frequency range 250--1250 Hz. We summarized the results of the studies regarding the effect of the flow around the blade profile, characterized by the Reynolds number, on the vortex noise intensity. Findings of research show that the exponent of the dependence of the vortex sound intensity on the characteristic velocity around the blade profile in various ranges of the Reynolds number can vary significantly. When changing the value of lg Re in the range from 1.8 to 5, the final dependence of growth rate exponent first falls from 6 to 3, remains equal to 3 in the range of lg Re from 2.65 to 3.2, and then again increases to 6 for lg Re in the range from 3.4 to 3.7, and with an even larger increase, the exponent increases from 7 to 8 and above (to 11) to lg Re = 4.5. At higher Reynolds numbers, (over 106) corresponding to self-similar modes of flow around the blades of light propeller aircraft, the exponent is 5. Based on the study, we recommend using one of the well-known trailing edge noise models for calculating the vortex noise of propellers at the sketch design stage. The paper also introduces the main methods formulated for reducing the intensity of the vortex sound of rotating blades

show abstract

Sound radiation by distributed quadrupole sources near rigid bodies

Cited by 2 publications

References 6 publications

Experimental study of a noise reduction concept for realistic landing gear geometries

Experimental study of a noise reduction concept for realistic landing gear geometries

Study of Vortex Noise of Rotating Blades

Contact Info

Product

Resources

About