Lanterna Rally

Author: Christopher P. Durand

Publisher:

Published: 2016

Total Pages: 92

ISBN-13:

In this work, the solution of the NASA Glenn Research Center Broadband Aeroacoustic Stator Simulation (BASS) Computational Aeroacoustics (CAA) code to a benchmark problem has been presented. The test case used for this work is the Category 3 problem from the NASA Second CAA Workshop on Benchmark Problems, which is a 2D gust--cascade problem involving the interaction of an incident vortical gust with a row of infinitely thin stator blades. It has been found that BASS accurately predicts the magnitude of the cut-on acoustic modes that result from the gust impinging on the blades for both the low frequency and the high frequency benchmark case. Spurious reflections from the upstream and downstream boundaries are present in the solution due to limitations of the boundary conditions. Absorbing layers were used to minimize reflections from the boundary, with favorable results achieved by both using absorbing layers and increasing the axial length of the computational domain. Results also have been presented that suggest that dispersion relation-preserving (DRP) spatial differencing schemes may not accurately resolve the decay rate of decaying acoustic waves with an economical number of grid points per wavelength. This work does not suggest a solution to this issue, but provides a general overview of the problem in order to help form a basis for future research.