| Texto completo | |
| Autor(es): |
Moura, R. C.
[1]
;
Silva, A. F. C.
[1]
;
Bigarella, E. D. V.
[2]
;
Fazenda, A. L.
[3]
;
Ortega, M. A.
[1]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] ITA, Sao Jose Dos Campos, SP - Brazil
[2] EMBRAER, Commercial Aviat, Sao Jose Dos Campos, SP - Brazil
[3] UNIFESP, Sao Jose Dos Campos, SP - Brazil
Número total de Afiliações: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Computational Physics; v. 319, p. 9-27, AUG 15 2016. |
| Citações Web of Science: | 2 |
| Resumo | |
This paper proposes two important improvements to shock-capturing strategies using a discontinuous Galerkin scheme, namely, accurate shock identification via finite-time Lyapunov exponent (FTLE) operators and efficient shock treatment through a point-implicit discretization of a PDE-based artificial viscosity technique. The advocated approach is based on the FTLE operator, originally developed in the context of dynamical systems theory to identify certain types of coherent structures in a flow. We propose the application of FTLEs in the detection of shock waves and demonstrate the operator's ability to identify strong and weak shocks equally well. The detection algorithm is coupled with a mesh refinement procedure and applied to transonic and supersonic flows. While the proposed strategy can be used potentially with any numerical method, a high-order discontinuous Galerkin solver is used in this study. In this context, two artificial viscosity approaches are employed to regularize the solution near shocks: an element-wise constant viscosity technique and a PDE-based smooth viscosity model. As the latter approach is more sophisticated and preferable for complex problems, a point-implicit discretization in time is proposed to reduce the extra stiffness introduced by the PDE-based technique, making it more competitive in terms of computational cost. (C) 2016 Elsevier Inc. All rights reserved. (AU) | |
| Processo FAPESP: | 12/16973-5 - Soluções numéricas de problemas complexos de dinâmica dos fluidos por meio de técnicas espectrais tipo Galerkin Descontínuo |
| Beneficiário: | Marcos Aurélio Ortega |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |