Library Subscription: Guest

ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

UNSTEADY NATURAL CONVECTION IN AN ENCLOSURE

Get access (open in a dialog) DOI: 10.1615/IHTC11.2800
pages 341-356

Abstract

An overview is made of time-dependent buoyant convection in an enclosure. Interest is confined to the situations in which buoyancy plays a significant role, i.e., the system Rayleigh number is large. Convective motions arise in response to the imposition of time-varying boundary conditions. An important common thread is the division of flow into distinct boundary layers and an inviscid interior core. The classical treatises on the transient adjustment of a fluid to an abrupt change of stratification are reviewed, and the relevant time scales are identified. A description is given of the overall transient process in a sidewall-heated rectangular cavity when a step change in sidewall temperature is introduced. Several other issues of current concern in more realistic model representations are discussed. Considerable attention is given to unsteady natural convection in an enclosure with temporally-periodic thermal and/or mechanical boundary conditions. The occurrence of resonance in the context of confined buoyant convection is pointed out. The basic physical mechanism and possible prediction techniques for resonance are explored.