A generalised Riemann problem-based compact reconstruction method for finite volume schemes

We present a Generalised Riemann Problem-based reconstruction method (GRPrec) for high-order finite volume schemes applied to hyperbolic partial differential equations. The method constructs spatial polynomials using cell averages at the current time level and GRP solution data from the previous time level. The resulting GRPrec stencil is as compact as that of discontinuous Galerkin (DG) schemes, but unlike DG, our finite volume schemes obey a generous CFL stability condition that is independent of the order of accuracy. We assess the method's performance through test problems for smooth and discontinuous solutions of the linear advection equation and the Euler equations of gas dynamics in one space dimension. Results are compared against exact solutions and against numerical results from well-known spatial reconstruction finite volume and DG schemes, with all methods implemented in the fully discrete ADER framework. The performance of GRPrec is very promising, especially in terms of efficiency, that is, the error against CPU cost.