Effect of viscosity on impedance eduction and validation
2016 (English)In: 21st AIAA/CEAS Aeroacoustics Conference, American Institute of Aeronautics and Astronautics, 2016Conference paper (Refereed)Text
Acoustic liners are a key part for reducing aircraft engine noise. Simulation and optimization of liner properties are critically relying on impedance measurement results, so called impedance eduction technology. Traditionally the effect of viscosity has been assumed to have negligible influence. However this paper shows that viscosity has noticeable influence even at low frequencies. The investigation is based on a comparison study using Linearized Euler equations and Linearized Navier-Stokes equations solved by finite element simulations. In the process of impedance eduction a one-dimensional straightforward method is proposed. Normal velocity and displacement have been obtained and discussed. Impedance results are further implemented into a two-dimensional wave propagation code. Finally simulation results have been compared and validated against experimental data.
Place, publisher, year, edition, pages
American Institute of Aeronautics and Astronautics, 2016.
Acoustic impedance, Aeroacoustics, Aircraft engines, Finite element method, Linearization, Viscosity, Wave propagation, Finite element simulations, Impedance eduction, Impedance measurement, Linearized EUler equation, Linearized navier-stokes equations, Simulation and optimization, Straight-forward method, Two-dimensional waves, Navier Stokes equations
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-188235ScopusID: 2-s2.0-84962553655ISBN: 9781624103674OAI: oai:DiVA.org:kth-188235DiVA: diva2:937449
21st AIAA/CEAS Aeroacoustics Conference, 2015, 22 June 2015 through 26 June 2015
QC 201606152016-06-152016-06-092016-06-15Bibliographically approved