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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

AN INVESTIGATION OF CHAOS IN POOL BOILING USING A 3D COUPLED MAP LATTICE MODEL

Get access (open in a dialog) DOI: 10.1615/IHTC13.p9.140
10 pages

Resumo

In the present paper, an investigation of chaos is carried out for the atmospheric pool boiling of water on a thin horizontal copper strip using a 3D coupled map lattice method based simulation of Gupta and Ghoshdastidar(2005). A CML is a dynamical system with discrete time, discrete space and continuous states. It usually consists of dynamical elements on a lattice which interact (are ‘coupled’) with suitably chosen sets of other elements. Basically, in this method a (set of) macroscopic variable(s) is chosen on a lattice. The basic physical processes underlying the phenomenon are then decomposed into independent components. Each component is then replaced by a simple parallel dynamics on a lattice. Finally, each unit dynamics (or procedure) is carried out successively. In order to understand the nonlinear characteristics of pool boiling, spatially averaged near-wall temperature fluctuation is employed as time-series, and its power spectrum and return map are discussed. Temperature is considered as the only field variable for the purpose of time-series analysis. The pool boiling is treated as a discrete dynamical system which is spatially extended and evolves in time. The Fast Fourier Transform (FFT) for pool boiling is found to be broad band noisy spectra. An attractor is constructed from the time-series data using the time delay method. The chaos is quantified in terms of Lyapunov exponent. It is found that near CHF the Lyapunov exponent has maximum positive value.