Environmental Engineering Reference
In-Depth Information
Fig. 2
Isotherms and stream
function for the enclosure
heated from
below
and
ʵ
=
0
.
3,
ʓ
=
0
.
1and
10
3
,
ʛ
=
1
/
5.
a
Ra
=
10
−
6
.
ʔˈ
=
2
.
8
×
10
4
,
b
Ra
=
10
−
6
.
ʔˈ
=
8
.
6
×
10
5
,
ʔˈ
=
9
.
1
×
10
−
3
.
d
Ra
=
10
6
,
ʔˈ
=
8
.
5
×
10
−
2
c
Ra
=
Fig. 3
Isotherms and stream
function for the enclosure
heated from
below
,
Ra
10
5
,
=
ʓ
=
0
.
1and
ʵ
=
0
.
3.
a
ʛ
=
1
/
10,
10
−
6
.
ʔˈ
=
7
.
4
×
b
ʛ
=
1
/
3,
10
−
2
ʔˈ
=
1
.
1
×
the dimensionless wavelength is large. The effect of
on the flow velocity may be
estimated by the increments of the stream function values,
ʛ
, corresponding to
each figure. The heat transfer through the cavity is also strongly dependent on the
dimensionless wavelength for high Rayleigh numbers. Figure
4
presents the aver-
age Nusselt number on the heating surface as a function of the Rayleigh number
for
ʔˈ
ʛ
=
1
/
10
,
1
/
5
,
1
/
3, aspect ratio
ʵ
=
0
.
3, and dimensionless wave amplitude
1. For Rayleigh numbers lower than 10
4
, the heat transfer is mainly due to
conduction and the average Nusselt number is 1
ʓ
=
0
.
10
4
the average
.
74. Above
Ra
=
Search WWH ::
Custom Search