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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

MIXED CONVECTION IN A HORIZONTAL DUCT ; A CHAOTIC SYSTEM

Get access (open in a dialog) DOI: 10.1615/IHTC10.3170
pages 417-421

Abstract

The influence of mixed convection due to buoyancy in the case of flow in a heated horizontal duct has been observed. This effect is characterized by the gradient of the temperature between the top and the bottom in a cross section measured by infrared thermography.

An increasing of the fluid velocity leads to an instability phenomenon (see figure 3 ) which occuring with fluctuation versus time of the wall temperature The amplitude of these oscillations depend on the test section position and the fluid velocity.

Such system behaves like a nonlinear dynamical dissipative system leading to a chaotic system characterized by a strange attractor. More particularly, the correlation dimension of this latter will be studied versus the axial coordinate z and the fluid velocity v. We will show that the secondary flow are responsible of the instabilities structuration which allow a spacial evolution from a developed turbulence at the entry to a chaotic system with fewer degrees of freedom.