Non-homogeneous radiation and outflow boundary conditions simulating incoming acoustic and vorticity waves for exterior computational aeroacoustics problems

• Published in: International journal for numerical methods in fluids 1998-05, Vol.26 (9), p.1107-1123
• Main Authors: Tam, Christopher K. W., Fang, Jun, Kurbatskii, Konstantin A.
• Format: Article
• Language: English
• Subjects: Acoustic noise; Acoustics; Aeroacoustics and atmospheric sound; Aeroacoustics, atmospheric sound; Aerodynamics; Boundary conditions; computational aeroacoustics; Computer simulation; Exact sciences and technology; Finite difference method; Fundamental areas of phenomenology (including applications); high-order finite difference solutions; Physics; radiation boundary conditions; scattering of sound or vorticity waves; Structural acoustics and vibration
• ISSN: 0271-2091; 1097-0363
• DOI: 10.1002/(SICI)1097-0363(19980515)26:9<1107::AID-FLD689>3.0.CO;2-N

A set of non‐homogeneous radiation and outflow boundary conditions which automatically generate prescribed incoming acoustic or vorticity waves and, at the same time, are almost transparent to outgoing sound waves produced internally in a finite computation domain is proposed. This type of boundary condition is needed for the numerical solution of many exterior aeroacoustics problems. In computational aeroacoustics, the computation scheme must be as non‐dispersive and non‐dissipative as possible. It must also support waves with wave speeds which are nearly the same as those of the original linearized Euler equations. To meet these requirements, a high‐order/large‐stencil scheme is often necessary. The proposed non‐homogeneous radiation and outflow boundary conditions are designed primarily for use in conjunction with such high‐order/large‐stencil finite difference schemes. © 1998 John Wiley & Sons, Ltd.