Estimating sound power from discrete measurements of sound intensity on a hemisphere

1989 ◽  
Vol 85 (S1) ◽  
pp. S11-S11 ◽  
Author(s):  
W. Weston Meyer
Keyword(s):  
Sound Intensity ◽  
Sound Power

Sound Radiation Characteristics of Lightweight Roof Constructions Excited by Rain

1994 ◽  
Vol 1 (4) ◽  
pp. 249-270 ◽  
Author(s):  
Hiromi Suga ◽  
Hideki Tachibana
Keyword(s):  
Transmission Loss ◽  
Power Level ◽  
Sound Radiation ◽  
Sound Intensity ◽  
Sound Power ◽  
Radiation Characteristics ◽  
Natural Rainfall ◽  
Artificial Rainfall ◽  
Sound Power Level ◽  
Measurement Results

In order to investigate the sound radiation characteristics of lightweight roof constructions when excited by rainfall, an artificial rainfall apparatus was constructed to simulate natural rainfall conditions. From the measurement results, it can be seen that the facility developed is practically applicable for the examination of the sound radiation characteristics of rain noise. It was therefore used in the measurement of sound power of 20 lightweight roofs. In addition, the relationship between sound power level and sound transmission loss measured by the sound intensity method was investigated statistically. As a result, it has been shown that a linear relationship exists between them and there is a possibility of estimating the sound power level from the transmission loss.

Determining sound power using sound intensity in a reverberation room and other spaces

1997 ◽  
Vol 101 (5) ◽  
pp. 3077-3078
Author(s):  
Robert Hickling ◽  
Peng Lee ◽  
Wei Wei
Keyword(s):  
Sound Intensity ◽  
Sound Power

Analysis of Combustion Noise Using Locally Resolved Density Fluctuations and a Microphone Array

2016 ◽  
Author(s):  
Johannes Peterleithner ◽  
Stefan Zerobin ◽  
Jakob Woisetschläger
Keyword(s):  
Microphone Array ◽  
Measurement Techniques ◽  
Time Derivative ◽  
Sound Intensity ◽  
Density Fluctuations ◽  
Combustion Noise ◽  
Sound Power ◽  
Direct Combustion ◽  
Laser Interferometric ◽  
Good Agreement

For turbulent swirl-stabilized flames combustion noise can be directly calculated, if density fluctuations as a function of time and space are known. It is however not easily possible to assess the density fluctuations directly. Therefore, in the past, combustion noise has been expressed as a function of chemiluminescence, an approach bringing in more assumptions. Now, by using interferometry, density fluctuations in the flame can be measured quantitatively. The advantage of this technique is that it measures the time derivative of density fluctuations directly. In this work laser interferometric vibrometry (LIV) was used to scan a two dimensional field in the flame in order to calculate the sound power emitted by the flame. Sound intensity was measured in a half-hemisphere by pressure-pressure-probes in order to record the total sound power of the direct combustion noise emitted by the unconfined flame. The goal of this study was to compare the measured sound power exhibited by the flame with the sound power predicted due to fluctuations of density within the flame. By using a siren to generate linear excitation, it was possible to qualitatively predict combustion noise with good agreement in trend. A quantitative comparison between both measurement techniques showed a deviation of a factor of six.

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