Sound pressure distribution

Figure 8.1.17 Sound-pressure distribution in a medium-intensity sound field. Radial and axial coordinates are scaled with the speed of sound Xo of pure water at 20kHz.

Figure 8.1.20 Simulation of the sound-pressure distribution in the crevice reactor with internal and external transducers. Dark areas represent zones with sound pressures...

The links between levels of exposure and inconvenience caused by ventilation noise are described in an investigation carried out on office workers.- Technical measurements and analyses of the ventilation noise at 155 typical office workplaces were in this study combined with assessments by the office workers of the level of disturbance that they experienced, the effect on working performance, fatigue, stress-related pain, and headaches. The average noise level was about 40 dB(A) at two of the workplaces, while it was about 35 dB(A) at two others. It emerged from rhe narrow-band analyses that the sound pressure levels of rhe infrasound were not in any event of an order that this type of sound frequencies (below 20 Hz) could contribute to any disturbance effects. Any steps taken to counter the sound frequencies of the ventilation noise under 50 Hz, i.e., the point of btersection between the threshold curve of auditory perception and the spectral level distribution curve of... 

Sufficiently high sound pressures in liquids create voids or gas- and vapor-filled bubbles. Any liquid has a theoretical tensile strength that characterizes the minimum pressure for disruption. Due to the presence of nuclei such as dissolved gases, solid impurities, and rough walls, cavitation occurs at far lower sound pressures than are theoretically necessary. In nearly any liquid, initial nuclei are present that show a distinct size distribution and grow under a certain sound pressure. Bubble growth, multiplication, and disappearance in a sound field is still a very complex phenomenon. 

The last piece for the model is the bubble-size distribution function and the limits for the rest radii of bubbles in the sound field. The cavitation thresholds as a function of applied sound pressure indicate the upper and lower size limits for bubbles in a cavitating sound field. A simplifying point of view would differentiate between a) transient bubbles, b) stable bubbles and c) dissolving bubbles. 

The proposed solution is the calculation of the bubble motion of bubbles with different sizes using the Kirkwood-Bethe-Gilmore equations. Knowing the bubble-size distribution at a given sound pressure by calculating cavitation thresholds and using this information in an equation for the local total bubble number, the calculation of the complex bulk modulus of the bubbly mixture is possible. 

The knowledge of the modal composition in sound fields including the magnitude and phase angle enables the calculation of the total spatial distribution of the sound pressures. Using the developed calculation procedure, the dynamic response of the circuit insulation resulting from the excitation by the sound field can be calculated. 

One sheet in the result report contains the result for behavior with the required changes in the noise power of the speakers. A second sheet contains the description of the behavior in the use case. First, there is the distributed architecmre of several frequency ranges with amphtude values measured by the microphone. These measurements represent the total sound pressure of all sounds in the application scenario. Secondly, the sound power levels of both speakers are registered across multiple frequency ranges. Along with the overall sound pressure measured by the microphone in the area and later determination of the position of the passenger, the... 

Ehara, Shiro Instantaneous pressure distributions of orchestra sounds, /. Acoust. Soc. Japan, vol. 22, pp. 276-289,1966. 

For n equal sources, each having the same sound pressure level L, distributed within a given space the mean level L in that space is approximately ... 

Dahnke, S. Swamy, K.M. Keil, F.J.A. A comparative study on the modeling of sound pressure field distribution in a sonoreador with experimental investigation. Ultrasonics Sonochem. v. 6, p. 221-226, 1999. 

The value of the measured Sabine absorption coefficient of a textile might be different with different sample sizes, sample distributions and properties of the room in which it is measured. Therefore, when values measured in a laboratory are used to calculate reverberation times and reverberant sound pressure levels in practical auditoria and factories, the calculated values are approximate only. 

When only one index is nonzero, the eigenmodes separate into longitudinal (n O), radial n 0) and azimuthal m 0) modes (Figure 5). In the other mixed eigenmodes the spatial distribution of the sound pressure is much more complicated. 

The question considered is a description of the conditions which must be met by a localized initiator if a spherical detonation wave is to be formed. The first problem is a determination of the possibility of the existence of such a wave. Taylor analyzed the dynamics of spherical deton from a point, assuming a wave of zero-reaction zone thickness at which the Chapman-Jouguet condition applies. He inquired into the hydrodynamic conditions which permit the existence of a flow for which u2 +c2 = U at a sphere which expands with radial velocity U (Here U = vel of wave with respect to observer u2 = material velocity in X direction and c -= sound vel subscript 2 signifies state where fraction of reaction completed e = 1). Taylor demonstrated theoretically the existence of a spherical deton wave with constant U and pressure p2equal to the values for the plane wave, but with radial distribution of material velocity and pressure behind the wave different from plane wave... 

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