ABSTRACT
It may be noted that Eq. (111) is a special case of Eq. (102) with z1e=0 (see Fig. 10). Consider Fig. 12. The initial profile in this case is given by segment EFG. It is clear that VD=Area (ABCD). Thus, the excess continuous phase in the upper part is V1′=Area (AEF) and the deficiency in the lower part is V2′=Area (BGF). Now, if V1′=V2′, we have ε0L0=VD and the continuous phase will simply redistribute so as to attain a final equilibrium profile given
by curve(AFB). However, if V1′<V2′, the lower part (FG) requires more continuous phase than can be provided by the upper part (EF), so that ε at the top falls below εc and the disperse phase separates out. This causes the length of the foam to decrease and the final
profile is given by curve(BFB1). In this case, the change in length is given by length (DC1).
