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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

ELASTIC STRESS ACTS ON ELASTIC TURBULENCE OF VISCOELASTIC FLUID FLOW IN CURVY MICROCHANNEL

Get access (open in a dialog) DOI: 10.1615/IHTC16.cov.023299
pages 3343-3350

Abstract

In very low Reynolds number flow condition, inertia force is almost negligible, Newtonian fluid flow shows regular laminar regime, while viscoelastic fluid flow can induce significant elastic stress and result in a chaotic flow, which is called elastic turbulence. We performed direct numerical simulation (DNS) on Newtonian fluid and viscoelastic fluid flows in a curvy channel. The log conformation reformulation (LCR) was used to solve the high Weissenberg number problem (HWNP). Flow patterns transition from laminar regime to elastic turbulent regime was achieved by increasing the Weissenberg number (Wi). The distinct flow regimes were confirmed by the variation of statistical character in different conditions. For the high Wi cases, the relationship between velocity inflection and fluctuation velocity is obtained. From the view of stress balance and energy budget, the process of elastic stress acting on the elastic turbulence flow is given. By analyzing the multi-physics field information in the cross section, the mechanism of elastic (hoop) stress acting on the velocity field and inducing elastic turbulence was firstly elucidated. This work paves the way for understanding the mechanism of elastic turbulence action process.