SIMULATING THE AXISYMMETRIC INTERFACIAL FLOWS WITH INSOLUBLE SURFACTANT BY IMMERSED BOUNDARY METHOD

Abstract

In this paper, we extend our previous work on the two-dimensional immersed boundary method for interfacial flows with insoluble surfactant to the case of three-dimensional axisymmetric interfacial flows. Although the key components of the scheme are similar in spirit to the two-dimensional case, there are two differences introduced in the present work. Firstly, the governing equations are written in an immersed boundary formulation using the axisymmetric cylindrical coordinates. Secondly, we introduce an artificial tangential velocity to the Lagrangian markers so that the uniform distribution of markers along the interface can be achieved and a modified surfactant concentration equation is derived as well. The numerical scheme still preserves the total mass of surfactant along the interface. Numerical convergence of the present scheme has been checked, and several tests for a drop in extensional flows have been investigated in detail.