Application of Azimuthal Decomposition Technique for Validation of CAA Methods

摘要

In the present paper a new strategy for validation of CAA methods is proposed. Azimuthal Decomposition Technique (ADT) elaborated and adapted for aeroacoustics measurements in TsAGI is considered from the viewpoint of validation of current jet noise computation techniques. Experimental techniques, of which ADT is a striking example, allowing extracting from turbulent flows nontrivial data (besides commonly accepted far-field noise directivity, power spectral density of total jet noise etc.) turn out to be very useful both for deeper physical insight into aeroacoustic mechanisms and for validation of CAA methods. When validated versus nontrivial experimental data sets, CAA methods will allow performing reliable analysis of all possible characteristics of turbulent flows, some of which can not even be measured in real experiments. In the present paper ADT is applied to the far acoustic field of subsonic jets modeled by LES based on CABARET method. Obtained characteristics of azimuthal modes agree well to the TsAGI's experimental database both in terms of azimuthal modes directivities and cross-correlation properties.