An improved RBF-WENO scheme for hyperbolic conservation laws

Abstract

In this paper, a novel fifth-order weighted essentially non-oscillatory (WENO) scheme by using radial basis function (RBF) is proposed to solve hyperbolic conservation laws. The key idea is to choose multi-quadric (MQ) RBF and trigonometric function to construct numerical flux and smoothness indicator respectively. First, we modify the RBF interpolation making it into the WENO reconstruction framework along with representing it by a perturbation of polynomial. The explicit form of disturbance term on each stencil is given. Through selecting the appropriate shape parameters of MQ RBF, the relevant WENO scheme achieves sixth-order accuracy than other well-known fifth-order WENO schemes under some conditions. Moreover, some differential operators based on trigonometric function space are employed to obtain new smoothness indicators that efficiently evaluates the sharp change of gradient on the candidate stencil. To highlight the effectiveness of the proposed WENO scheme, this new scheme is applied to several one and two-dimensional hyperbolic test problems, and compared with the existing schemes such as WENO-JS, WENO-M and WENO-Z. The numerical results show higher accuracy can be achieved in the smooth regions of the solutions, and no non-physical oscillations occur near the discontinuities, which verifies the higher resolution property and the better discontinuity-capturing ability of the improved scheme.