ON THE CAPABILITY OF UNSTEADY RANS COMPUTATIONS TO REPRODUCE NON-DETERMINISTIC PRESSURE DISTURBANCES FOR NOISE PREDICTIONS

摘要

Random pressure fluctuations arising from turbulent fluid flow represent a non-deterministic source of sound, which contributes to the overall emission from pro-pulsors. The present study therefore addresses the capability of unsteady fluid dynamics computations, with the Reynolds-averaged Navier-Stokes equations applied, to reproduce non-deterministic pressure disturbances in order to predict broadband noise. Investigations of an advanced propfan in a fully-turbulent flow regime typically experienced under take-off conditions are presented. In order to systematically conclude on the capability to reproduce broadband noise sources, the aeroacoustics are evaluated at different levels of aerodynamic loading and spatial discretisation.