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ESTENSIONE NAH per Noise Vision
Un nuovo modo di visualizzare il campo acustico 3D
The NAH (near-field acoustic holography) feature, using spherical antenna, is implemented on the system Noise Vision through an innovative scientific approach to predict the sound pressure and particle velocity around the measuring sphere, starting from the values of the sound pressures measured on the spherical sensor. Furthermore, it can also be calculated the sound intensity, in other word you can "see" the energy flow in the acoustic field (volume) around the transducer. The main interest of this extension of the Noise Vision system is the increase in efficiency at low frequencies, since the method NAH spherical can be used in small enclosed spaces such as the cab of the vehicle, is also useful for other advanced applications like for the acoustic modal analysis.
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ACOUSTIC IMAGES
The most advanced technologies to understand noise problems.
Several solutions are available to fit different requirements, presented by Nittobo Acoustic Engineer - Japan and DISTRAN - Switzerland. Even if the technological aspects are similar, the systems are rather different and focused on diversified applications.
The basic selection criteria is between the needs to identify noise sources in one specific direction (planar antenna) or in the 3d space around (spherical antenna), while the application shouuld consider the following: Machineries On-board sources: => near filed => Holografia Open field Noise sources : => far field => Beamforming Confined 3d spaces: => Spherical Beamforming
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