Determination of acoustic power levels of machines under service conditions

1983 ◽  
Vol 26 (10) ◽  
pp. 882-885
Author(s):  
O. N. Pobol'
Keyword(s):  
Acoustic Power ◽  
Service Conditions

On the Determination of the Acoustic Power of a Source of Sound in Semi‐Reverberant Spaces

Noise Control ◽  
1961 ◽  
Vol 7 (1) ◽  
pp. 21-29 ◽  
Author(s):  
R. J. Wells ◽  
Francis M. Wiener
Keyword(s):  
Acoustic Power

scholarly journals Nanogenerator for determination of acoustic power in ultrasonic reactors

2021 ◽  
pp. 105718
Author(s):  
Krystian Mistewicz ◽  
Marcin Jesionek ◽  
Hoe Joon Kim ◽  
Sugato Hajra ◽  
Mateusz Kozioł ◽  
...  
Keyword(s):  
Acoustic Power ◽  
Ultrasonic Reactors

Method of determination of acoustic power

2008 ◽  
Vol 40 (6) ◽  
pp. 537-539
Author(s):  
E. V. Rusina
Keyword(s):  
Acoustic Power ◽  
Method Of Determination

A Whistling Criterion for Two Orifices in Series

2009 ◽  
Author(s):  
Romain Lacombe ◽  
Yves Aure´gan ◽  
Pierre Moussou
Keyword(s):  
Pressure Drop ◽  
Power Plants ◽  
Acoustic Power ◽  
Scattering Matrix ◽  
In Series ◽  
Inner Diameter ◽  
Acoustic Amplifier ◽  
Experimental Criterion

Whistling phenomena in pipe power plants have been observed in the past years. It occurs at pressure drop devices where vortex shedding is established. It generates high noise levels and excessive vibrations. Aure´gan and Starobinsky [1] have developed an experimental criterion to predict whistling frequencies of pressure drop devices submitted to plane propagating pressure waves. This criterion estimates the net acoustic power, an acoustic exergy generation indicating that the device behaves as an acoustic amplifier. The corresponding frequencies are potential whistling frequencies. The application of the criterion only requires the determination of the scattering matrix of the device. In previous works, this criterion was applied to different single hole orifices. The purpose of the present study is to apply the criterion to two orifices in series and to verify that the behavior of this system can be predicted from the scattering matrix of each individual orifice and of the straight pipe in-between. Measurements are done on an air test rig with an inner diameter of 3 cm, a Mach number of 2.6 × 10−2 and a Reynolds number of 104. Different distances between orifices are characterized. The study of the influence of the second orifice on the whistling criterion shows an enhancement of the whistling potential and a shift of the main potential whistling frequency. A fair agreement is found between experimental and predicted results. Characterization of orifices in series is then possible from the coefficients of the scattering matrix of one orifice and an appropriate condition on the distance between the orifices.

Dynamic Mechanical Properties of Sugarcane

2013 ◽  
Vol 811 ◽  
pp. 314-318
Author(s):  
Jan Džugan ◽  
Martina Maresova ◽  
Pavel Podany
Keyword(s):  
Mechanical Properties ◽  
Dynamic Loading ◽  
Dynamic Mechanical Properties ◽  
Recent Time ◽  
Optimized Design ◽  
Material Optimization ◽  
New Material ◽  
Service Conditions ◽  
Increasing Demand

New design of a sugarcane shredder is being performed within a research project. This kind of equipment used to be traditionally designed on the basis experiences up to recent time. With increasing demand for the material economic utilization and reliable service, new material optimized design of shredders is required. In order to be able to perform qualified design and material optimization, service conditions has to be known. The paper is dealing with determination of sugarcane mechanical properties under dynamic loading, as the shredding process is performed at high velocities in the range of several meters per second. The mechanical properties of the sugarcane are going to be subsequently used for calculation of in operation loading on shredder components in the further steps.

scholarly journals THE LABORATORY INVESTIGATIONS OF HIGH-DENSITY POLYETHYLENE DRAINS FOR APPLICATION IN TAILINGS

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Mihailo Muravljov ◽  
Petar Anagnosti ◽  
Aleksandar R. Savić
Keyword(s):  
High Density Polyethylene ◽  
Tangential Direction ◽  
High Density ◽  
Test Results ◽  
Specific Behavior ◽  
Tailings Pond ◽  
Laboratory Investigations ◽  
Service Conditions ◽  
Under Construction

For the purposes of draining material deposited in the tailings pond under construction, there was aneed to examine the properties of the high-density polyethylene drain tubes and the consistingmaterials in order to assess their adequacy in the specific conditions. The conducted laboratoryinvestigations of the samples cut from the tubes included: determination of bulk density, tensilestrength in the tangential direction, as well as the compressive strength in a radial direction.Representative samples of the tubes themselves were tested in two different loading dispositions, inorder to record the load-deflection effects. The test results indicated the specific behavior of thetested material in service conditions.

Uniqueness of Solutions to Variationally Formulated Acoustic Radiation Problems

1990 ◽  
Vol 112 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Xiao-Feng Wu ◽  
Allan D. Pierce
Keyword(s):  
Acoustic Radiation ◽  
Axial Direction ◽  
Acoustic Power ◽  
Normal Derivative ◽  
Surface Velocity ◽  
Finite Cylinder ◽  
Uniqueness Of Solutions ◽  
Integral Theorem ◽  
Kirchhoff Integral

Determination of the surface acoustic pressure given the surface velocity of a vibrating body can be formulated in various ways. However, for some such formulations such as the surface Helmholtz integral equation, solutions are not unique at certain discrete frequencies. Such uniqueness problems can also be present for variational formulations of the problem, but the variational formulation based on the normal derivative of the Kirchhoff integral theorem has unique solutions for vibrating disks and plate-like bodies. For bodies of finite volume, but for which each surface point is vibrating in phase, the total radiated acoustic power is always unique, even though the pressure may not be. The latter conclusion is supported by numerical calculations based on the Rayleigh-Ritz technique for the case of a finite cylinder vibrating as a rigid body in the axial direction.

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