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标题：Response of Viscoelastic Turbulent Pipeflow Past Square Bar Roughness: The Effect on Mean Flow
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作者：Shubham Goswami ; Arman Hemmati
期刊名称：Computation
电子版ISSN：2079-3197
出版年度：2021
卷号：9
期号：8
页码：85
DOI：10.3390/computation9080085
语种：English
出版社：MDPI Publishing
摘要：The influence of viscoelastic polymer additives on response and recovery of turbulent pipeflow over square bar roughness elements was examined using Direct Numerical Simulations at a Reynolds number of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>5</mn><mo>×</mo><msup><mn>10</mn><mn>3</mn></msup></mrow></semantics></math></inline-formula>. Two different bar heights for the square bar roughness elements were examined, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>h</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>0.05</mn></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.1</mn></mrow></semantics></math></inline-formula>. A Finitely Extensible Non-linear Elastic-Peterlin (FENE-P) rheological model was employed for modeling viscoelastic fluid features. The rheological parameters for the simulation corresponded to a high concentration polymer of 160 ppm. Recirculation regions formed behind the bar elements by the viscoelastic fluid were shorter than those associated with Newtonian fluid, which was attributed to mixed effects of viscous and elastic forces due to the added polymers. The recovery of the mean viscoelastic flow was faster. The pressure losses on the surface of the roughness were larger compared to the Newtonian fluid, and the overall contribution to local drag was reduced due to viscoelastic effects.