Penetrative Convection in a Partially Open Enclosure.
Penetrative Convection in a Partially Open Enclosure.
(617 K)
Abib, A. H.; Jaluria, Y.
American Society of Mechanical Engineers (ASME).
Natural Convection in Enclosures. HTD-Vol. 192. 1992,
Am. Soc. of Mechanical Engineers, New York, NY, 73-81
pp, 1992.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Keywords:
enclosures; convection; heat sources; formulations;
equations; stratification; flow fields; temperature;
velocity distribution; penetration; heat transfer
Abstract:
The penetrative convection induced by a localized heat
source at the bottom of a partially open enclosure,
while the background ambient medium is stably and
thermally stratified, is considered. A rectangular
cavity with a partially open side is assumed to be
adjacent to a long corridor which is stably stratified.
The stable thermal stratification that is of interest is
a two-layered one or a linear temperature
stratification. A control-volume finite-difference
method, in stream function and vcorticity formulation,
is employed for the solution. The influence of the
stratification parameter is examined in the laminar flow
regime by considering a range of stratification levels.
Heat transfer results, mass outflow rate, penetration
distance, velocity and temperature distributions are
presented to quantify the penetrative convection. It is
found that, for a step ambient temperature profie, the
convective motion occurring in the lower unstable layer
penetrates significantly into the stable upper layer
only for a weak stratification. Small penetration
occurs at large stratification levels. The flow field
reveals a multi-cellular pattern. Furthermore, it is
observed that the penetrative motion occurs in the form
of nearly horizontal motion in the lowest part of the
stable upper-layer. The thermal field is studied in
detail. Other important details on the penetrative
transport are brought out.
