Document Type

Conference Paper

Publication Date

2022

DOI

10.2514/6.2022-2898

Publication Title

28th AIAA/CEAS Aeroacoustics 2022 Conference

Pages

1-16

Conference Name

28th AIAA/CEAS Aeroacoustics 2022 Conference, Southampton, UK, June 14-17, 2022

Abstract

A time domain boundary integral equation with Burton-Miller reformulation is presented for acoustic scattering by surfaces with liners in a uniform mean flow. The Ingard-Myers impedance boundary condition is implemented using a broadband multipole impedance model and converted into time domain differential equations to augment the boundary integral equation. The coupled integral-differential equations are solved numerically by a March-On-in-Time (MOT) scheme. While the Ingard-Myers condition is known to support Kelvin-Helmholtz instability due to its use of a vortex sheet interface between the flow and the liner surface, it is found that by neglecting a second derivative term in the current time domain impedance boundary condition formulation, the instability can be effectively suppressed in computation. Proposed formulation and implementation are validated using NASA Langley Research Center Grazing Flow Impedance Tube (GFIT) experimental dataset with satisfactory results. Moreover, a minimization procedure for finding the poles and coefficients of the broadband multiple impedance model is formulated in this paper by which, unlike the commonly used vector-fitting method, passivity of the model is ensured. Numerical tests show the proposed minimization approach is effective for modeling liners that are commonly used in aeroacoustics applications.

Comments

Copyright © 2022 by F. Q. Hu.

Included with the kind written permission of the copyright holder.

Original Publication Citation

Hu, F. Q., & Nark, D. M. (2022). On the implementation and further validation of a time domain boundary element method broadband impedance boundary condition. 28th AIAA/CEAS Aeroacoustics 2022 Conference. Southampton, United Kingdom. https://doi.org/10.2514/6.2022-2898

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