Benchmarking Rod–Airfoil Aeroacoustics Using Higher-Order Flux-Reconstruction Scheme

An implicit large-eddy simulation (ILES) is performed on the rod–airfoil benchmark case coupled with a time-domain Ffowcs Williams–Hawkings acoustic analogy formulation to predict aeroacoustic noise. The compressible Navier–Stokes equations are solved using the high-order solver PyFR, an open-source framework for solving advection-diffusion problems using high-order flux reconstruction schemes. Reynolds number based on the airfoil chord length is 480,000, and the Mach number M is 0.21. This study evaluates the applicability and accuracy of high-order flux reconstruction in an ILES framework for computational aeroacoustics focusing on both aerodynamics and acoustic predictions. PyFR simulations predict the dominant tonal frequency at a Strouhal number of 0.18. The far-field acoustic spectra show good agreement with the published literature. The influence of spanwise resolution domain length is quantified, demonstrating that spanwise resolution has a modest effect on the near-field aerodynamics and far- field acoustics, whereas the spanwise domain length has a substantially stronger impact. The individual noise contributions from the rod and airfoil are analyzed and reveal that the airfoil dominates the overall noise except at very high frequencies. Constructive interference between the two sources leads to elevated overall sound pressure levels. Directivity analysis confirms that the radiated sound field exhibits a predominantly dipolar pattern.