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0.875 0.5
0.02925ReTi Sca
ev wa
k D
(3.84)
Based on the conditions here, an average value of 2.67×10 -5 m 2 /s for D wa is used for
simplifying the computation.
Based on the analysis above, condensation rate at the same place can be expressed as:
m 1.2 k A ( C C )
(3.85)
cndns ev Tli Tsv Tav
m cndns is condensation rate and quantitatively equals to 120% of evaporation rate but
with opposite sign because CTsv CTav
when condensation is occurring.
Eq. (3.83) and Eq. (3.85) can be combined as:
m k k A ( C C )
(3.86)
Tlec ec ev Tli Tsv Tav
Where m Tlec is HADT lump inner surface condensation or evaporation rate, kec may be
named as condensation-to-evaporation coefficient. When CTsv CTav
, evaporation may
occur and kec 1.
When CTsv CTav
, condensation occurs and kec 1.2 .
Integration of positive part of m Tlec within a breath cycle gives the cycle-wise total
amount of potential evaporation and integration of negative part of m Tlec within a breath
cycle gives that of condensation.
And:
mTlecP kev ATli ( CTsv CTav ) dt
when CTsv CTav
0 (3.87)
mTlecN 1.2 kev ATli ( CTsv CTav ) dt when CTsv CTav
0 (3.88)
mTlec mTlecP mTlecN
(3.89)
The sum of the two integrals gives the net condensation or evaporation within a breath
cycle on inner surface of this lump. If the sum is positive, it means there is no
condensation remaining within a whole breath cycle. It may mean that there is no
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