A general interaction potential model between plateau borders to determine the strain rate of liquid foams

In this paper we present a general model based on interactions between plateau borders to determine the strain rate of the two dimensional liquid foam. It is found that a defect length is responsible for the stress concentration and thus the flow of cells through the foam. The flow is local. The underlying assumption is that the area of the unit cell which undergoes a T1 process remains invariant. This leads to the persistant of the defect length which is responsible for the flow. It is found that the strain rate is given as where c is a constant, is the number per unit length of the persistant length, b is the displacement of the cells and νl is the rate of contraction of the persistent length.