Simulation of noise radiation from installed pusher propeller aircraft configurations (Section 8.3)

Kurzfassung

The aeroacoustic phenomena characteristic of a pusher-propeller configuration and their aerodynamic causes are discussed and analyzed. The work was done in the frame of the European-funded project CESAR (Cost Effective Small AiRcraft). The configuration under study is an industrially relevant design with a wing-mounted pusher propeller, which features a close coupling of the turboshaft engines exhaust nozzles and a five bladed propeller. The coupling of an Actuator Disc (TAU AD) model and unsteady free wake panel method (UPM) is employed for the computation of the propeller unsteady aerodynamic force in "pusher" installations. The Ffowcs-Williams/Hawkings (FW-H) equations based code APSIM is used to compute the sound propagation into the far field. A detailed comparison of the current fast coupling method with high-fidelity uRANS (TAU) simulation results and the differences between the two approaches are discussed. The noise reduction through a redesigned engine exhaust nozzle is presented.