Investigating the Numerical Stability of Using an Impedance Boundary Condition to Model Broadband Noise Scattering With Acoustic Liners
Proceedings of the AIAA Aviation 2020 Forum
AIAA Aviation 2020 Forum, Virtual, June 15-19, 2020
Reducing aircraft noise is a major objective in the field of computational aeroacoustics. When designing next generation quiet aircraft, it is important to be able to accurately and efficiently predict the acoustic scattering by an aircraft body from a given noise source. Acoustic liners are an effective tool for achieving aircraft noise reduction and are characterized by a frequency-dependent impedance value. Converted into the time-domain using Fourier transforms, an impedance boundary condition can be used to simulate the acoustic wave scattering by geometric bodies treated with acoustic liners. A Broadband Impedance Model will be discussed in which the liner impedance is specified along a wide range of frequencies. The liner impedance boundary condition will be derived and coupled with a time-domain boundary integral equation to model acoustic scattering by a flat plate consisting of both un-lined and lined surfaces. The scattering solution will be obtained iteratively using both spatial and temporal basis functions and the stability will be demonstrated through eigenvalue analysis. Stability will be assessed for its dependence on time step, spatial discretization, as well as temporal basis function order. Both second- and third-order backward difference Lagrange temporal basis functions are considered.
Original Publication Citation
Rodio, M. E., Hu, F. Q., & Nark, D. M. (2020). Investigating the numerical stability of using an impedance boundary condition to model broadband noise scattering with acoustic liners. AIAA Aviation 2020 Forum, Virtual, June 15-19, 2020. https://doi.org/10.2514/6.2020-2547
Rodio, Michelle E.; Hu, Fang Q.; and Nark, Douglas M., "Investigating the Numerical Stability of Using an Impedance Boundary Condition to Model Broadband Noise Scattering With Acoustic Liners" (2020). Mathematics & Statistics Faculty Publications. 170.
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