An enhanced wavenumber-extended finite volume scheme for non-uniform grid system

摘要

The focus of the present study is to improve the numerical accuracy of wavenumber-extended finite volume scheme in non-uniform grid system. The basic idea is modification of cell flux interpolation function by evaluating a dispersion and dissipation error at a local cell position. An optimization procedure results optimized cell flux interpolation function to minimize dispersion and dissipation errors, In addition, to eliminate excessive numerical dissipation in the continuous region, a distinguishing step is modified to predict the suitable approximation value in non-uniform grid system. A modification of wavenumber-extended finite volume scheme is able to enhance the numerical accuracy of calculation of aeroacoustic problems in non-uniform grid system. An adoption of modified distinguishing step is able to implement e-MLP in non-uniform grid system. In order to investigate an improvement in numerical accuracy, simple numerical verification cases are carried out. Through the numerical tests such as acoustic pulse scattering and moving vortex preservation problems on non-uniform grid system, the proposed scheme is proven to have better numerical accuracy than the original wavenumber-extended finite volume scheme.