کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
656260 1457683 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Numerical simulation of a precessing vortex breakdown
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Numerical simulation of a precessing vortex breakdown
چکیده انگلیسی

The objective of this work is to present the results of time-dependent numerical predictions of a turbulent symmetry breaking vortex breakdown in a realistic gas turbine combustor. The unsteady Reynolds-averaged Navier–Stokes (URANS) equations are solved by using the k–ϵ two-equation model as well as by a full second-order closure using the Reynolds stress model of Speziale, Sarkar and Gatski (SSG). The results for a Reynolds number of 5.2 × 104, a swirl number of 0.52 and an expansion ratio of 5 show that the flow is emerging from the swirler as a spiral gyrating around a zone of strong recirculation which is also asymmetric and precessing. These flow structures which are typical for the spiral type (S-type) vortex breakdown have been confirmed by PIV and local LDA measurements in a corresponding experimental setup. Provided that high resolution meshes are employed the calculations with both turbulence models are capable to reproduce the spatial and temporal dynamics of the flow.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Fluid Flow - Volume 27, Issue 2, April 2006, Pages 192–203
نویسندگان
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