Abstract
The present work is on bifurcation and stability of fully-developed forced convection in a tightly curved rectangular duct. Seven symmetric and four asymmetric solution branches were found. The physical mechanism and driving forces for generating various flow structures are discussed. The flow stability on various branches is determined by direct transient computation on dynamic responses of the multiple solutions. As Dean number increases, finite random disturbances lead the flows from a stable steady state to another stable steady state, a periodic oscillation, an intermittent oscillation, another periodic oscillation and a chaotic oscillation. The features of flow oscillations are examined by Hilbert spectral analysis. The mean friction factor and the mean Nusselt number are obtained for all physically-realizable flows. A significant enhancement of heat transfer can be achieved at the expense of a slight increase of flow friction.
Original language | English |
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Pages (from-to) | 5849-5866 |
Number of pages | 18 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 52 |
Issue number | 25-26 |
DOIs | |
Publication status | Published - Dec 2009 |
Externally published | Yes |
Keywords
- Curved duct
- Forced convection
- Hilbert spectral analysis
- Multiplicity
- Stability
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes