1. By convention, most of the equations in this paper treat pressure drop as a negative value. For consistency, the following equations should have the negative signs added as shown below:  
dPdxslug=0.3164Reslug0.25ρLUslug22Dh
(1)
 
dPdxf/b=0.3164Rebubble0.25ρVUbubbleUinterface24Rbubble
(2)
 
ΔPonetransition=ρLUslugUfilm22
(3)
 
ΔPonetransition=ρL1RbubbleRtube2UslugUfilmUbubbleUfilm
(4)

2. In addition, Eq. (33) above had a factor of 2 in the denominator, which should be removed, as shown above.

3. The value of the coefficient, a, in Eq. (35), currently listed as 2436.9 in the text following the equation, should be changed to a=2.4369.