Open AccessDisturbing effects of a cylinder-form macro-roughness on the turbulent free-convection boundary layer: Large Eddy Simulation
Author(s) -
Alexander M. Levchenya,
E. V. Kolesnik,
Е. М. Смирнов
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1400/7/077031
Subject(s) - mechanics , turbulence , boundary layer , cylinder , natural convection , physics , large eddy simulation , vortex , heat transfer , geometry , classical mechanics , mathematics
The paper presents results of eddy-resolving numerical simulation of non-isothermal turbulent flow in the vicinity of an adiabatic circular cylinder that disturbs the turbulent free-convection boundary layer developing along a vertical heated plate. The computational domain used includes (i) a relatively long section, where the upstream free-convection boundary layer goes over to its natural state from the model state prescribed at the inlet boundary with a synthetic turbulence generator, (ii) a mid-section covering the disturbing cylinder, mounted normally on the plate, (iii) an outlet section that is much longer than the cylinder diameter. The mathematical model is based on the Navier-Stokes equation written with the Boussinesq approximation. In the case simulated, the height of the cylinder (equal to its diameter) is about two times less than the approaching boundary layer half-width, if estimated from the velocity profile. Characteristic features of unsteady phenomena in the flow disturbed by the macro-roughness are analyzed with a focus on behavior of arising horseshoe-like vortex structures. Quantitative data on heat transfer augmentation near the cylinder is presented.