Conference_programme: 2.1 - Aeroacoustics
Lecture: Flow acoustic modeling of a slit resonator using linearized Navier-Stokes equations
Author(s): Vandemaele Simon, Denayer Hervé, Tournadre Jonathan, De Roeck Wim, Desmet Wim
Summary:
Sound mitigation strategies for flow duct systems often incorporate Helmholtz resonators to attenuate low frequency noise. This paper models the linear, flow acoustic behavior of a slit resonator, mounted at the side of a flow duct, under grazing acoustic excitation. The calculations are performed in two steps to limit computational effort. First the mean flow field is resolved with steady, incompressible RANS simulations on a refined structured grid. Thereafter, the acoustic field and its mean flow interactions are calculated in 2D on a coarser, unstructured grid by means of an in-house parallelized acoustic propagation solver. A seventh order Discontinuous Galerkin discretization of the linearized Navier-Stokes equations, combined with an optimized Runge-Kutta time integration, is herein used. The results are post-processed as an acoustic two-port model and compared to experimental data. \n\nComparison between experiments and simulations shows good agreement. The model correctly predicts the band-stop filter behavior around the resonance frequency, which shifts to higher frequencies with increasing Mach number. Also the effect of increased damping at higher flow rates is correctly described. However, compared to the quiescent case, the grazing flow causes slightly larger quantitative discrepancies between the measurements and the simulated results. In an extension of the model, aerodynamic simulations are performed in 3D to further investigate the effect of the mean flow description on the accuracy of the model.\n
Corresponding author
Name: Mr Simon Vandemaele
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Belgium
