Natural convection in attics subject to instantaneous and ramp cooling boundary conditions

Saha, Suvash C., Patterson, John C., & Lei, Chengwang (2010) Natural convection in attics subject to instantaneous and ramp cooling boundary conditions. Energy and Buildings, 42(8), 1192-1204 .

View at publisher


A fundamental study of the fluid dynamics inside an attic shaped triangular enclosure with cold upper walls and adiabatic horizontal bottom wall is reported in this study. The transient behaviour of the attic fluid which is relevant to our daily life is examined based on a scaling analysis. The transient phenomenon begins with the instantaneous cooling and the cooling with linear decreases of temperature up to some specific time (ramp time) and then maintain constant of the upper sloped walls. It is shown that both inclined walls develop a thermal boundary layer whose thicknesses increase towards steady-state or quasi-steady values. A proper identification of the timescales, the velocity and the thickness relevant to the flow that develops inside the cavity makes it possible to predict theoretically the basic flow features that will survive once the thermal flow in the enclosure reaches a steady state. A time scale for the cooling-down of the whole cavity together with the heat transfer scales through the inclined walls has also been obtained through scaling analysis. All scales are verified by the numerical simulations.

Impact and interest:

31 citations in Scopus
Search Google Scholar™
25 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

Full-text downloads:

83 since deposited on 21 Aug 2011
14 in the past twelve months

Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.

ID Code: 44110
Item Type: Journal Article
Refereed: Yes
Keywords: Natural convection, Ramp cooling, Boundary layer, Unsteady flow, Cooling down time
DOI: 10.1016/j.enbuild.2010.02.010
ISSN: 03787788
Subjects: Australian and New Zealand Standard Research Classification > ENGINEERING (090000) > MECHANICAL ENGINEERING (091300) > Numerical Modelling and Mechanical Characterisation (091307)
Divisions: Past > QUT Faculties & Divisions > Faculty of Built Environment and Engineering
Past > Schools > School of Engineering Systems
Copyright Owner: Copyright 2010 Elsevier S.A.
Deposited On: 21 Aug 2011 23:59
Last Modified: 27 Mar 2013 19:27

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page