Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1016/j.compfluid.2017.04.016

Ключевые слова: Non-circular straight duct, Second normal stress difference, Secondary flow, Viscoelastic fluid, Aspect ratio, Budget control, Computational fluid dynamics, Ducts, Flow patterns, Geometry, Viscoelasticity, CFD (computational fluid dynamics), Crosssectional geometry, Geometrical configurations, Normal stress difference, Straight duct, Sufficient and necessary condition, Vis-coelastic fluids, Viscoelastic fluid flows, Flow of fluids

Аннотация: Numerical simulations were conducted on viscoelastic fluid flows in straight ducts with different cross sections, for which the origin of secondary flows and influences of material parameters and flow passage geometrical configuration were numerically investigated. The Giesekus constitutive model was chosen to describe the viscoelastic fluid with the second normal stress difference N2, and solved by embedding UDF (User-defined Function) into the CFD (computational fluid dynamics) code FLUENT. The origin of such kind of secondary flow was theoretically studied from the perspective of the budget of vorticity energy for the first time. Sufficient and necessary condition for the existence of secondary flow was then developed in terms of N2, the gradient of N2 and cross-sectional geometry ? (i.e., generation term E?). Moreover, helicity density was considered as an excellent indicator of secondary flow pattern. Effects of material properties (including anisotropic parameter?, solvent viscosity ratio ? and relaxation time ?) and flow passage geometrical configuration (aspect ratio of cross sectionsr, the number of polygon sides n) on secondary flow strength and pattern were investigated with E?. Finally, a universal variable ?s was proposed to describe non-circularity of cross section, based on which the results for ducts with different cross sections can be normalized together. © 2017 Elsevier Ltd

Журнал: Computers and Fluids

Выпуск журнала: Vol. 152

Номера страниц: 57-73

• Li Yu-Ke (Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Peoples R China)
• Zheng Zhi-Ying (Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Peoples R China)
• Zhang Hong-Na (Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Peoples R China)
• Li Feng-Chen (Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Peoples R China)
• Qian Shizhi (Old Dominion Univ, Inst Micro Nanotechnol, Norfolk, VA 23529 USA)
• Joo Sang Woo (Yeungnam Univ, Sch Mech Engn, Gyongsan 712719, South Korea)
• Kulagina Ludmila V. (Siberian Fed Univ, Dept Environm Engn & Life Safety, Krasnoyarsk 660041, Russia)

• Scopus
• Web of Science Core Collection
• Ядро РИНЦ (eLIBRARY.RU)