6 Conclusions
This paper has introduced a new method for the analysis of the tonal noise radiated from non-axisymmetric turbofan inlets. It combines a standard FE discretisation of the acoustic field in the axial and radial coordinates with a Fourier spectral representation in the circumferential direction. As a relatively small number of Fourier modes are enough for an accurate field representation, the method is far less costly than the conventional 3D FE approach. The most novel feature of the work is the iterative solution technique using a preconditioner based on an axisymmetric geometry and steady flow field. A numerical example illustrates how few Fourier modes need to be retained, and demonstrates the effectiveness of the preconditioner.
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Duta, M.C., Giles, M.B., Laird, A. (2006). A Hybrid FE/Spectral Analysis of Turbofan Aeroacoustics. In: Groth, C., Zingg, D.W. (eds) Computational Fluid Dynamics 2004. Springer, Berlin, Heidelberg . https://doi.org/10.1007/3-540-31801-1_6
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DOI: https://doi.org/10.1007/3-540-31801-1_6
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