1.0
(b)
(c)
(a)
10
Dry
Dry
Dry
0.8
Ta = 25 C
φ = 50 %
Tfb = 0 C
5
θ
35
70
30
60
0.6
Ta = 25 C
Tfb = 0 C
U = 4 m/s
Dew Points
0.4
Ta = 25 C
φ = 50 %
φ = 50 %
Tfb = 0 C
U = 4 m/s
U = 4 m/s
0.2
1.0 0
0.2
0.4
0.6
0.8
1.0 0
0.2
0.4
0.6
0.8
1.0
0
0.2
0.4
0.6
0.8
ξ
ξ
ξ
Figure 14. Effects of dry bulb temperature, relative humidity, and fin base temperature on the
temperature distributions in a vertical rectangular fin. Adapted from Coney et al. (1989).
1.0
2.4
Tfb = 0 C
φ = 50%
2.0
Ta =35 C
25
qwt
qws
0.9
30
30
qd
qd
25
1.6
35
(b)
(a)
0.8
1.2
0.8
0.8
25
0.6
0.6
35
30
qws
q
w
35
30
qwt
qwt
25
0.4
0.4
Figure 15. Sensible, latent, and
(c)
(d)
total heat transfers for wet ver-
0.2
0.2
tical rectangular fins. Adapted
0
0.4
0.8
1.2
0
0.4
0.8
1.2
Bi
Bi
from Coney et al. (1989).
how the sensible and latent heat transfers, as a fraction of the total heat transfer for wet
conditions, qwt, are affected by Bi and Ta.
The paper by Coney et al. (1989a) also gives the results for the condensate film thick-
ness ∆. These results indicate that ∆ increases as Ta and φ increase, or as Tfb decreases.
However, the study concluded that the effect of film thermal resistance can be neglected
without introducing significant error for normal conditions encountered in practice. On
23
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