Aeroacoustic Analysis of a Subsonic Jet using the Discontinuous Galerkin Method

In this work, the open-source spectral/hp element framework Nektar++ (www.nektar.info)
is coupled with the Antares library (www.cerfacs.fr/antares/) to predict noise from a subsonic
jet. Nektar++ uses the high-order discontinuous Galerkin method to solve the compressible
Navier-Stokes equations on unstructured grids. Unresolved turbulent scales are modeled using
an implicit Large Eddy Simulation approach. In this approach, the favourable dissipation
properties of the discontinuous Galerkin method are used to remove the highest resolved
wavenumbers from the solution. For time-integration, an implicit, matrix-free, Newton-Krylov
method is used. To compute the far-field noise, Antares solves the Ffowcs Williams - Hawkings
equation for a permeable integration surface in the time-domain using a source-time dominant
algorithm. The simulation results are validated against experimental data obtained in the Doak
Laboratory Flight Jet Rig, located at the University of Southampton.