Numerical study of the stress singularity in stick-slip flow of the Phan-Thien Tanner and Giesekus fluids

Autor(es)

Evans, J. D. ^[1] ; Cuminato, J. A. ^[2] ; Palhares Junior, I. L. ^[2] ; Oishi, C. M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Bath, Dept Math Sci, Bath BA2 7AY, Avon - England

^[2] Univ Sao Paulo, Inst Ciencias Matemat & Comp, Dept Matemat Aplicada & Estat, BR-13566590 Sao Carlos, SP - Brazil

^[3] Univ Estadual Paulista, Fac Ciencias & Tecnol, Dept Matemat & Comp, BR-19060900 Presidente Prudente, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physics of Fluids; v. 31, n. 9 SEP 2019.
• Citações Web of Science: 0

Resumo

Stick-slip flow is a challenging viscoelastic benchmark problem due to the presence of a separation or transition point at the die exit where a sudden change in flow boundary conditions occurs. We present numerical simulations of transient planar stick-slip flow of the Phan-Thien-Tanner (PTT) and Giesekus fluids, investigating the polymer stress behavior around the stress singularity at the stick-slip point, confirming the asymptotic results presented by Evans et al. {[}{''}Stresses of the Oldroyd-B, PTT and Giesekus fluids in a Newtonian velocity field near the stick-slip singularity,{''} Phys. Fluids 29, 1-33 (2017)]. In order to improve the numerical knowledge about this viscoelastic benchmark problem, two distinct mathematical methodologies are used for comparison in the computational simulations: the Cartesian and natural stress formulations. The former is widely applied in computational rheology, while the latter is used for the first time in the context of this problem. The natural stress formulation gives improved convergence results both temporally and spatially near to the singularity while maintaining the same global flow characteristics as the Cartesian. (AU)

• Processo FAPESP: 13/07375-0 - CeMEAI - Centro de Ciências Matemáticas Aplicadas à Indústria
• Beneficiário: José Alberto Cuminato
• Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/22242-0 - Escoamentos com superfície livre de fluidos complexos
• Beneficiário: Murilo Francisco Tome
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/17348-2 - Estabilidade de métodos numéricos para escoamentos viscoelásticos com alto número de Weissenberg
• Beneficiário: Irineu Lopes Palhares Junior
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 16/20389-8 - Estudo numérico do tensor na formulação natural para problemas com superfície livre
• Beneficiário: Irineu Lopes Palhares Junior
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado