کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
658314 1458082 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Double-diffusive buoyancy convection in a square cuboid with horizontal temperature and concentration gradients
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Double-diffusive buoyancy convection in a square cuboid with horizontal temperature and concentration gradients
چکیده انگلیسی
Double-diffusive buoyancy convection in a three-dimensional (3D) square cuboid is studied in the present paper. Both the temperature and solute concentration gradients are applied horizontally. Direct numerical simulations are carried out for Rayleigh number 10≤Ra≤2×105, buoyancy ratio -2≤Rρ≤0, and Lewis number 2≤Le≤1000. Different front-rear symmetric solutions are found, and the flow structures are essentially three-dimensional. As each of the parameters is varied, typical pitchfork bifurcation is encountered, given appropriate disturbances. The resultant asymmetric solution presents a diagonal flow configuration. Different solution branches are denoted in terms of Nusselt and Sherwood numbers and corresponding two-dimensional (2D) model results are also presented to depict the deviations. In some parameter ranges, the 2D model significantly over-predicts the heat and mass transfer rates. More importantly, it fails to predict any unsteadiness of the flow, even when the corresponding 3D solution is chaotic. The onset of convection from the quiescent equilibrium state is also considered.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 60, May 2013, Pages 422-431
نویسندگان
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