A comparison of line-sources of buoyancy placed near and far from a wall
File(s)
Accepted version
Author(s)
Parker, David
Burridge, HC
Partridge, Jamie
Linden, Paul
Type
Conference Paper
Abstract
Experiments are presented on turbulent
buoyant free
-
line and wall plumes,
whereby the buoyancy source is
emitted from a horizontal line source, in one case free of the presence of
a wall and in the other placed
immediately adjacent to a wall. The dynamics of turbulent entrainment, whereby ambie
nt fluid is mixed in to the
plume, are explored. The velocity field and scalar edge of the plumes are measur
ed. From this the time
-
averaged
plume
-
width and volume flux are compared. The spreading rate, and therefo
re the entrainment, of the wall plume
is fo
und to be half that of the free
-
line plume, indicating that the wall has a signif
icant effect on the entrainment
process.
Further, the volume flux of the wall plume is found to be half that of the free
-
line plume, indicating that
larger maximum scalar conc
entrations are present in the wall plume.
The effect that the reduced entrainment rate
has on a typical heated room,
via a line source of buoyancy,
is demonstrated by comparing a numerical model of
the develo
ping temperature stratification within a sealed
enclosure in the case of the line source near a wall and
away from a wall
, where
in particular it is
found that higher maximum temperatures are present for the case of
the line source near a wall
.
buoyant free
-
line and wall plumes,
whereby the buoyancy source is
emitted from a horizontal line source, in one case free of the presence of
a wall and in the other placed
immediately adjacent to a wall. The dynamics of turbulent entrainment, whereby ambie
nt fluid is mixed in to the
plume, are explored. The velocity field and scalar edge of the plumes are measur
ed. From this the time
-
averaged
plume
-
width and volume flux are compared. The spreading rate, and therefo
re the entrainment, of the wall plume
is fo
und to be half that of the free
-
line plume, indicating that the wall has a signif
icant effect on the entrainment
process.
Further, the volume flux of the wall plume is found to be half that of the free
-
line plume, indicating that
larger maximum scalar conc
entrations are present in the wall plume.
The effect that the reduced entrainment rate
has on a typical heated room,
via a line source of buoyancy,
is demonstrated by comparing a numerical model of
the develo
ping temperature stratification within a sealed
enclosure in the case of the line source near a wall and
away from a wall
, where
in particular it is
found that higher maximum temperatures are present for the case of
the line source near a wall
.
Date Issued
2017-09-13
Date Acceptance
2017-06-01
Citation
38th AIVC Conference, 2017
Journal / Book Title
38th AIVC Conference
Copyright Statement
© 2017 The Author(s)
Source
38th AIVC Conference: Ventilating healthy low-energy buildings
Publication Status
Published
Start Date
2017-09-13
Coverage Spatial
Nottingham, UK