The Ffowcs-Williams and Hawkings Analogy for Full Aircraft Noise Prediction

This study investigates the influence of different Ffowcs Williams and Hawkings (FW– H) formulations on far-field noise prediction for a propeller-driven strut-braced wing aircraft. High-fidelity flow data were obtained using the Lattice–Boltzmann Very-Large-Eddy Simulation (LB-VLES) solver PowerFLOW^®, and acoustic predictions were carried out using the permeable-surface, solid-surface, and volumetric FW–H analogies included in the ™ toolkit. Results show that the permeable formulation reproduces both the amplitude and directivity of the dominant tonal lobes in good agreement with the noise directly extracted from the CFD simulation. The solid formulation, instead, exhibits discrepancies in regions exposed to the impingement of propeller-generated sound waves, where pressure fluctuations are detected but not correctly propagated. The volumetric approach, while computationally demanding, provides valuable physical insight by confirming the absence of actual radiating sources on that part of the fuselage. For similar configurations, the permeable formulation represents the most reliable and computationally efficient choice for predicting far-field noise.