Open AccessVisualization of instability processes in pure thermal plume
Author(s) -
Egor Kuznetsov,
E. V. Kolesnik,
Evgenii Khrapunov
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 - 10.1088/1742-6596/1382/1/012020
Subject(s) - plume , mechanics , instability , convection , convective flow , flow (mathematics) , flow visualization , natural convection , bifurcation , thermal , visualization , boundary layer , thermodynamics , materials science , meteorology , physics , computer science , nonlinear system , quantum mechanics , artificial intelligence
In the paper, the results of physical and numerical simulation of a natural convective flow formed over a heated horizontal disk are presented. The main purpose of this study is to analyze the occurrence of various stable states of a free-convection plume depending on the temperature of the heated surface. The presented flow patterns make it possible to determine the critical value of the temperature factor at which a change of stable states is observed. The visualization data obtained in the framework of physical modeling are compared and supplemented with data on flow patterns obtained numerically. A mechanism for the formation of separate air masses (“puffs”), which destroy both the near-wall layer and the formed upward flow is proposed. It was found that the emerging soft bifurcation is characterized by a sharp increase in the amplitude of perturbations with a slight increase in the value of the temperature factor: initial fluctuations of the plume boundary lead to further disruption of the heat balance and formation of puffs.