کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
670924 1459073 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The UCM limit of the PTT equations at a re-entrant corner
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
The UCM limit of the PTT equations at a re-entrant corner
چکیده انگلیسی

We consider the Upper Convected Maxwell (UCM) limit of the Phan-Thien–Tanner (PTT) equations for steady planar flow around re-entrant corners. The PTT equations give the UCM equations in the limit of vanishing model parameter κ  , this dimensionless parameter being associated with the quadratic stress terms in the PTT model. We show that the critical length scale local to the corner is r=Oκ12(1−α) as κ → 0, where π/α is the re-entrant corner angle with α ∈ [1/2, 1) and r the radial distance. On distances far smaller than this we obtain the PTT κ = 1 problem, whilst on distances greater (but still small) we obtain the UCM problem κ = 0. This critical length scale is that on which intermediate behaviour of the PTT model is obtained where both linear and quadratic stress terms are present in the wall boundary layer equations. The double limit κ → 0, r → 0 thus yields a nine region local asymptotic structure.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Newtonian Fluid Mechanics - Volume 165, Issues 21–22, November 2010, Pages 1543–1549
نویسندگان
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