Verification of a Multi-Time-Step Adams-Bashforth (MTSAB) Time-Marching Scheme Using External Verification Analysis (EVA)

摘要

Problems encountered in the field of Computational Aeroacoustics frequently exhibit a large range of time scales. The choice of time step is determined by the smallest time scale present and the stability limit of the time-marching scheme used, which may lead to excessively small time step sizes in areas of the flow where they are not needed, and thus long simulation runs. Recently, an automated multi-time step Adams-Bashforth-style time-marching scheme has been implemented in a high-order CAA code that allows different time step sizes to be assigned in different areas of the problem domain based on local accuracy or stability requirements. The implementation of this scheme — referred to here as the Multi-Time-Step Adams-Bashforth, or MTSAB, scheme — assigns the time steps block-by-block automatically with no intervention necessary on the part of the user. In this work, a variant of the Method of Manufactured Solutions called External Verification Analysis (EVA) is used to rigorously Verify a two-dimensional implementation of the MTSAB scheme.