03.1 - Aerodynamics – CFD Methods and Validation
HIGH FIDELITY MODELING OF ACOUSTIC LINERS FOR AERONAUTICAL APPLICATIONS
L. Pinelli¹, M. Marconcini¹, A. Arnone ¹, D. Bacci, Oxford Thermofluids Institute, University of Oxford, United Kingdom; ¹Department of Industrial Engineering, University of Florence, Italy
Aircraft noise is a polluting emission from civil aviation and is the most significant cause of adverse community reaction related to the operation and expansion of airports. Reducing the population affected by significant aircraft noise is therefore a key priority for aircraft-engine designers. rnAcoustic liners are a well-established technology to abate noise emissions and they have been installed in the engine intake and turbine nozzle from a long time. Such passive devices are usually designed to absorb a target band of the noise spectrum radiated from the aft and rear part of the engine.rnLiner panes based on single-degree-of-freedom cavities are usually designed by means of semi-analytical methods and verified with experimental campaign in dedicated grazing tube rig. Thanks to the growth in computational capability, high fidelity simulations of such devices are becoming viable and can be used instead of expensive experimental campaigns. This is particularly true when screening non-conventional geometries of the resonator cavity as Triply Periodic Minimal Surface (TPMS).rnIn this context, the paper presents and validates a high-fidelity numerical approach based on the OpenFOAM opensource CFD code to predict the acoustic impedance and absorption of liner panels. LES simulations of a single resonator cell have been performed with and without grazing flow for different Sound Pressure Level (SPL) of the planal acoustic waves to investigate linear and non-linear regimes of the resonator. Liner impedance and absorption coefficients have been derived by mean of the well-know in-situ method.rn