Title: Direct Numerical Simulation on drag-reducing flow by polymer additives using a spring-dumbbell model

Authors: Yi Wang, Bo Yu, Jin-jia Wei, Feng-chen Li, Yasuo Kawaguchi

Addresses: Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum (Beijing), 102249, People's Republic of China. ' Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum (Beijing), 102249, People's Republic of China. ' State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. ' School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China. ' Faculty of Science and Technology, Department of Mechanical Engineering, Tokyo University of Science, Noda 278-8510, Japan

Abstract: A discrete-element model (spring-dumbbell model) is used to investigate the mechanism of drag-reduction by adding polymer in a turbulent channel flow of Newtonian fluid by Direct Numerical Simulations (DNSs). By using this model, the spatial concentration of the polymer can be obtained numerically. In this paper, the effect of the spring coefficient on the drag-reduction is studied in detail. The quantitative relations between the drag-reduction rate and viscoelastic and Reynolds shear stress, etc., are obtained. Discussions are performed to clarify the relation between the turbulent structure of the polymer drag-reducing flow and the spring coefficient of the discrete-element model.

Keywords: spring-dumbbell model; DNS; direct numerical simulation; drag reduction; turbulent channel flow; polymer additives; discrete element modelling; spring coefficient; flow simulation.

DOI: 10.1504/PCFD.2009.024822

Progress in Computational Fluid Dynamics, An International Journal, 2009 Vol.9 No.3/4/5, pp.217 - 224

Published online: 01 May 2009 *

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