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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

PROSPECTS FOR EFFICIENT ENHANCED HEAT TRANSFER IN AN OPEN CHAOTIC FLOW

Get access (open in a dialog) DOI: 10.1615/IHTC13.p20.30
13 pages

Resumo

The enhanced transport characteristics of laminar chaotic flows is studied numerically in the context of heat transfer in the Rotated Arc Mixer (RAM) (Metcalfe et al 2006). We study heat transfer in a 2D analogue of the RAM for a Newtonian fluid in the Stokes regime with temperature acting as a passive scalar. Flow behaviour in this instance is governed by a number of design and operational parameters, controlling the topology of the Lagrangian dynamics. For a fixed Peclét number, an optimisation problem can be formulated in which these control parameters are selected so to maximise heat transfer. A novel spectral method is employed to solve the governing advection-diffusion equation for temperature in a highly efficient manner over the RAM parameter space. This method directly yields numerical approximations to the so-called “strange eigenmodes” (Lui and Haller 2004) of the system; the dominant ones of which dictate asymptotic behaviour and determine all but the short-time heat transfer rate. As the asymptotic heat transfer rate over the parameter space is fractal, high resolution non-localised scans are undertaken to identify global optima and understand fundamental phenomena. Results suggest improvements of 650% and 700% respectively in heat transfer rate over that of diffusion only for fixed temperature and fixed flux boundary conditions respectively at Pe = 103, which moreover increase with Peclét number.