Calibration of projection-based reduced-order models for unsteady compressible flows

Autor(es)

Zucatti, Victor ^[1] ; Wolf, William ^[1] ; Bergmann, Michel ^{[2, 3, 4]}

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, BR-13086860 Campinas - Brazil

^[2] INRIA, Memphis Team, F-33400 Talence - France

^[3] Univ Bordeaux, IMB, UMR 5251, F-33400 Talence - France

^[4] CNRS, IMB, UMR 5251, F-33400 Talence - France

• Tipo de documento: Artigo Científico
• Fonte: Journal of Computational Physics; v. 433, MAY 15 2021.
• Citações Web of Science: 0

Resumo

An analysis of calibration for reduced-order models (ROMs) is presented in this work. The Galerkin and least-squares Petrov-Galerkin (LSPG) methods are tested on compressible flows involving a disparity of temporal scales. A novel calibration strategy is proposed for the LSPG method and two test cases are analyzed. The first consists of a subsonic airfoil flow where boundary layer instabilities are responsible for trailing-edge noise generation and the second comprises a supersonic airfoil flow with a transient period where a detached shock wave propagates upstream at the same time that shock-vortex interaction occurs at the trailing edge. Results show that calibration produces stable and long-time accurate Galerkin and LSPG ROMs for both cases investigated. The impact of hyper reduction is tested on LSPG models via an accelerated greedy missing point estimation (MPE) algorithm. For the first case investigated, LSPG solutions obtained with hyper reduction show good comparison with those obtained by the full order model. However, for the supersonic case the transient features of the flow need to be properly captured by the sampled points of the accelerated greedy MPE method. Otherwise, the dynamics of the moving shock wave are not fully recovered. The impact of different time-marching schemes is also assessed and, differently than reported in literature, Galerkin models are shown to be more accurate than those computed by LSPG when the non-conservative form of the Navier-Stokes equations is solved. For the supersonic case, the Galerkin and LSPG models (without hyper-reduction) capture the overall dynamics of the detached and oblique shock waves along the airfoil. However, when shock-vortex interaction occurs at the trailing-edge, the Galerkin ROM is able to capture the high-frequency fluctuations from vortex shedding while the LSPG presents a more dissipative solution, not being able to recover the flow dynamics. (C) 2021 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 19/18809-7 - Estratégias de modelagem de ordem reduzida para simulação de escoamentos não estacionários
• Beneficiário: Victor Zucatti da Silva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado
• Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/11410-9 - Utilização da análise de componentes principais para a construção de modelos de ordem reduzida
• Beneficiário: Victor Zucatti da Silva
• Modalidade de apoio: Bolsas no Brasil - Mestrado