Entry flow and constitutive modelling of fluid S1

被引:14
作者
Byars, JA [1 ]
Binnington, RJ [1 ]
Boger, DV [1 ]
机构
[1] UNIV MELBOURNE,DEPT CHEM ENGN,PARKVILLE,VIC 3052,AUSTRALIA
关键词
entry flow; S1; Giesekus model; Phan-Thien-Tanner model; Papanastasiou et al model;
D O I
10.1016/S0377-0257(97)00034-7
中图分类号
O3 [力学];
学科分类号
08 ; 0801 ;
摘要
Experimental observations of the flow through an axisymmetric 4:1 contraction for the shear-thinning test fluid S1 are presented. In order to provide the basis for comparison with numerical simulations of the flow, the linear viscoelastic spectrum and the nonlinear parameters for three constitutive models are also obtained, based on the rheological characterisation of the fluid by Ooi and Sridhar [J. Non-Newtonian Fluid Mech. 52 (1994) 121-135]. The Phen-Thien-Tanner model provides the best fit to the data, but a good fit can also be obtained for the Giesekus model if the fit to the extensional stress growth coefficient is restricted to low strains. The results of flow visualisation experiments are presented for the flow of S1 through a 4:1 axisymmetric contraction with either an abrupt entry or a rounded re-entrant corner. The dimensionless vortex size increased with Weissenberg number for each geometry, with a larger vortex observed for the abrupt entry geometry for identical flow conditions. No elastic lip vortex or flow instability was observed for We less than or equal to 5.0. (C) 1997 Elsevier Science B.V.
引用
收藏
页码:219 / 235
页数:17
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