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In the entrainment regime
of entrainment, the amplitude
parameter for the description
slightly modified by using the
as
The motion
shear flow
T. = 0.005 1 + C
g h
0.005 C
g h
of the wave
model (Ishii
Ti= C wuf of.(19)
v
1
PqJ 2
g
crest
and
beyond the critical gas velocity for the onset
of the wave crest should be the most important
of T.. Therefore, the above correlation is
1
wave amplitude instead of the film thickness
1 .2
P gJ g
with respect to
Grolmes [14]) as
the film may
(18)
be expressed by a
On the other hand, interfacial shear force can also be expressed by the liquid
friction factor as
2
Ti = fiPZvf (20)
From Eqs. (19) and (20) one can eliminatetvf and obtain an expression for the
amplitude as
Pf
a = C Pf
w PfTi
1
"V=7i
A typical liquid friction factor
film thickness given by Hughmark
number regime of interest,
Substituting
interfacial
= 1.13 Re f0.25
Eqs. (21) and
shear force can
can be
[28].
obtained
Thus for
(22) into Eq. (18) a
be derived.
162
(21)
from the correlation for a
a relatively high Reynolds
following
(22)
expression for the