OVERVIEW OF THE EXPERIMENTAL DETERMINATION OF ACOUSTIC FLOW ON THE BASIS OF SOUND INTENSITY MEASUREMENTS

A large variety of CFD/CAA hybrid approaches are commonly used today for aero-acoustic engineering applications using equations and the coupling between source and acoustic propagation region. The coupling is usually made using Lighthill’s acoustic analogies and Kirhchoff’s acoustic boundary conditions. This paper intends to give answer how the size and shape of the source may be influence on the accuracy of the different coupling methods and their sensitivity. In this way, some experimental investigation was made using sound intensity measurement technique to the graphic presentation of the spatial distribution of the acoustic power flow over various geometrical shapes of structures located in a three-dimensional space. The results of these studies contribute to the theory of sound and general knowledge about the physics of flow acoustic phenomena, especially in the near acoustic field. As a result of research, the visualization analysis of the sound intensity flux in 3D space is shown as flow wave reactions on the presence of obstacles with different shapes. The results of vectors flow fields around a rectangular and circular plate, over the cavity and inside a ducts are show. The visualization of acoustic power flow in real-life acoustic fields can explain many particular energetic acoustic effects like scattering, vortex flow in shielding area, etc., concerning areas where it is difficult to make numerical analysis.