Airfoil noise computation use high-order schemes

High-order finite difference schemes with at least 4th-order spatial accuracy are used to simulate aerodynamically generated noise. The aeroacoustic solver with 4th-order up to 8th-order accuracy is implemented into the in-house flow solver, EllipSys2D/3D. Dispersion-Relation-Preserving (DRP) finite difference schemes and optimized high-order compact finite difference schemes are applied for acoustic computation.

Acoustic equations are derived using so-called splitting technique by separating the compressible NS equations into viscous (flow equation) and inviscid (acoustic equation) parts. The viscous flow equations are solved using EllipSys2D/3D, the hydrodynamic variables are used as input to the inviscid acoustic equations at same time step.