An embedded shock-fitting technique on unstructured dynamic grids

In this paper, a new shock-fitting technique based on unstructured dynamic grids is proposed to improve the performances of the unstructured boundary shock-fitting technique developed by Liu and co-workers in [1, 2]. The main feature of this new technique, which we call the embedded shock-fitting technique, is its capability to insert or remove shocks or parts thereof during the calculation. This capability is enabled by defining subsets of grid-points (mutually connected by lines) which behave as either common- or shock-points, shock-waves being made of an ordered collection of shock-points. Two different sets of flow variables, corresponding to the upstream and downstream sides of the shocks, are assigned to the shock-points, which may be switched to common- and back to shock-points, a feature that allows to vary the length of the existing shocks and/or make new shock-branches appear. This paper illustrates the algorithmic features of this new technique and presents the results obtained when simulating both steady and un-steady, two-dimensional flows. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper introduces a new technique called the "embedded shock-fitting technique" with the capability to insert or remove shocks during the calculation. By defining subsets of grid-points, which can act as common- or shock-points, the length of existing shocks can be varied or new shock-branches can appear as needed.