Analytical models based on a mode-matching technique for turbulence impingement noise on axial-flow outlet guide vanes
Résumé
The proposed paper deals with the analytical modeling of the turbulence impingement noise on axial-flow outlet guide vanes. The methodology relies on two major steps. Firstly, the turbulent velocity field must be expanded into a set of oblique vortical gusts, the magnitude of which is related to turbulent velocity statistics. Secondly, the sound generation due to the impingement of these vortical gusts on a cascade of vanes is predicted using a mode-matching technique. Modeling the vanes as zero-thickness flat plates axially aligned, the methodology is applied first in a two-dimensional context, resorting to a strip-theory approach with several independent rectilinear cascades, and then in a three-dimensional context with an annular cascade accounting for non-parallel vanes and inner and outer rigid wall conditions. The latter is believed a more accurate geometrical representation of the vanes at the price of a simplified modeling of the flow and its turbulence. A comparison on a realistic rotor-stator test-case with both approaches is performed.