{"title":"HYPERBOLIC MODELS OF UNSTEADY FLOWS OF VISCOELASTIC FLUIDS","authors":"V.Yu Liapidevskii, V.V. Neverov, S.R. Karmushin","doi":"10.1134/S0021894424050110","DOIUrl":null,"url":null,"abstract":"<p>Unsteady one-dimensional shear flows of a viscoelastic fluid are considered. A general approach is formulated for fluids with several relaxation times, which allows the known models of viscoelastic flows to be presented as evolutionary systems of first-order equations. Conditions of hyperbolicity of flow classes considered are found for the Johnson–Segalman, Giesekus, and Rolie-Poly models. The equations of motion of the viscoelastic fluid are presented in the form of a full nonlinear system of conservation laws. A method of calculating unsteady discontinuous flows within the framework of the models under consideration is proposed. The class of unsteady Couette flows in the gap between the cylinders used in rheological tests is studied numerically. The process of shear banding and its influence on the structure of steady flows are investigated. The numerical results obtained are compared with experimental data.</p>","PeriodicalId":608,"journal":{"name":"Journal of Applied Mechanics and Technical Physics","volume":"65 5","pages":"895 - 906"},"PeriodicalIF":0.5000,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Mechanics and Technical Physics","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1134/S0021894424050110","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
Unsteady one-dimensional shear flows of a viscoelastic fluid are considered. A general approach is formulated for fluids with several relaxation times, which allows the known models of viscoelastic flows to be presented as evolutionary systems of first-order equations. Conditions of hyperbolicity of flow classes considered are found for the Johnson–Segalman, Giesekus, and Rolie-Poly models. The equations of motion of the viscoelastic fluid are presented in the form of a full nonlinear system of conservation laws. A method of calculating unsteady discontinuous flows within the framework of the models under consideration is proposed. The class of unsteady Couette flows in the gap between the cylinders used in rheological tests is studied numerically. The process of shear banding and its influence on the structure of steady flows are investigated. The numerical results obtained are compared with experimental data.
期刊介绍:
Journal of Applied Mechanics and Technical Physics is a journal published in collaboration with the Siberian Branch of the Russian Academy of Sciences. The Journal presents papers on fluid mechanics and applied physics. Each issue contains valuable contributions on hypersonic flows; boundary layer theory; turbulence and hydrodynamic stability; free boundary flows; plasma physics; shock waves; explosives and detonation processes; combustion theory; multiphase flows; heat and mass transfer; composite materials and thermal properties of new materials, plasticity, creep, and failure.