کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
670976 | 1459074 | 2010 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The dynamics of a simple model for a thixotropic yield stress fluid The dynamics of a simple model for a thixotropic yield stress fluid](/preview/png/670976.png)
We study the dynamics of a model for thixotropic yield stress fluids which was recently proposed in [1]. This is based on the partially extended convected model (PEC), modified to allow for a non-zero shear stress limit for large shear rates (PECR), and combined with a Newtonian solvent to enable yielding to homogeneous shear flow (PECR-N) under a prescribed shear stress. We define ϵ to be the ratio of retardation time to relaxation time and focus on the limit ϵ → 0. Multiple time scales arise and the solutions are investigated with perturbation methods, in conjunction with direct computation of the full set of equations. Both PEC-N and PECR-N capture the experimentally observed phenomenon that the value of yield stress depends on the observation time. For the PECR-N model, we find transient solutions that are not expected from prior work on the PEC-N model, such as blow-up in finite time on the slow manifold, and yielded time-periodic flow.
Journal: Journal of Non-Newtonian Fluid Mechanics - Volume 165, Issues 19–20, October 2010, Pages 1373–1385