AEROACOUSTICS AND PERFORMANCE MODELING OF A COUNTER-ROTATING PROPFAN

摘要

This paper presents a method for design and analysis of counter-rotating propfans with respect to performance and aeroacoustics. The preliminary design method generates the ideal optimum propeller design corrected for losses in terms of profile and compressibility drag. The propeller design is further analyzed by computational fluid dynamics, CFD, to calculate the performance and the deterministic interaction noise. The unsteady flow around the propellers is calculated using URANS such that only one blade per propeller needs to be discretized. The unsteady pressure distribution around the blades is integrated, using a Ffowcs Williams-Hawkings method, to an observer for noise evaluation. The results of the performance analysis, the CFD computations and the aeroacoustic analysis are compared with experimental data available from the non-proprietary reports regarding the counter-rotating propellers developed in the 1980s.