ISSN Online: 2377-424X
ISBN Print: 0-89116-909-1
International Heat Transfer Conference 9
LINEAR RESPONSE OF THE TEMPERATURE AND FLOW FIELDS IN A SQUARE ENCLOSURE TO IMPOSED WALL TEMPERATURE OSCILLATIONS
Abstract
The present numerical study is directed towards buoyancy driven laminar flow in a two-dimensional square enclosure with differential heating at the vertical walls. The top and bottom walls are insulated. A time-dependent sinusoidally varying perturbation is imposed at the hot vertical wall while the cold wall is maintained at a constant temperature. The results for a Prandtl number of 0.72 indicate that for perturbation amplitudes sufficiently small the heat transfer and flow field oscillations are directly proportional to the perturbation amplitude. In this linear regime, the oscillatory response behavior in the enclosure for the complete ranges of small, large and intermediate Rayleigh number and frequencies are determined and physically discussed. For larger amplitudes the response also becomes amplitude dependent, and exhibits a nonlinear behavior. The critical amplitude of the imposed oscillations for the onset of nonlinearity is found to be a strong function of the Rayleigh number.