کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8085238 1521753 2015 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
CFD study of an air-water flow inside helically coiled pipes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی مهندسی انرژی و فناوری های برق
پیش نمایش صفحه اول مقاله
CFD study of an air-water flow inside helically coiled pipes
چکیده انگلیسی
The effect of the centrifugal force field introduced by the geometry is characterized. Water is pushed by the centrifugal force towards the outer pipe wall, whereas air accumulates in the inner region of the pipe. The maximum of the mixture velocity is therefore shifted towards the inner pipe wall, as the air flows much faster than the water, having a considerably lower density. The flow field, as for the single-phase flow, is characterized by flow recirculation and vortices. Quantitatively, the simulation results are validated against the experimental data of Akagawa et al. (1971) for the void fraction and the frictional pressure drop. The relatively simple model of momentum interfacial transfer allows obtaining a very good agreement for the average void fraction and a satisfactory estimation of the frictional pressure drop and, at the same time, limits the computational cost of the simulations. Effects of changes in the diameter of the dispersed phase are described, as its value strongly affects the degree of interaction between the phases. In addition, a more precise treatment of the near wall region other than wall function results in a better definition of the liquid film at the wall, although an overestimation of the frictional pressure drop is obtained.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Nuclear Energy - Volume 85, November 2015, Pages 462-472
نویسندگان
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