Application of the Wave-Based Discontinuous Galerkin Method to Lined Ducts with Flow

The wave-based discontinuous Galerkin method (wave-based DGM) utilises plane waves instead of polynomials to approximate the solution in each element, drastically reducing the pollution error in the solution. This permits very accurate solutions with far fewer degrees of freedom than standard finite element or finite difference solvers. This paper presents further developments of the method based around predicting sound attenuation in lined ducts with flow. Accurate boundary condition formulations are described for a modal exit plane and an impedance surface. Two impedance formulations are demonstrated, a standard pressure substitution condition and a characteristic based condition. Results are presented illustrating the convergence against a mode matching scheme for a duct with flow and lined walls. I