STUDY OF MOLECULAR DIFFUSION IN OSCILLATING FLOW IN A PIPE USING THE BOUNDARY ELEMENT METHOD

Abstract

The effect of flow oscillations on the axial diffusion of a solute in a pipe is analyzed by the boundary element method (BEM). The equation governing fluid flow is solved analytically, and from these results, the concentration equation is solved by the BEM, employing the fundamental solution of the heat equation for a general initial distribution. Since the fundamental solution itself contains a time variable, there is no need to have a separate iteration for time. The boundary and the domain are generated as in the finite element method, and these integral equations are solved with linear variations, flow variables such as velocity and skin friction are calculated, and back flow and distribution of concentration are also discussed.