An immersed boundary method for simulations of flow and mixing in micro-channels with electro kinetic effects

Abstract

Immersed boundary method (IBM) is a methodology in which any real stationary or moving complex bodies in flow or heat transfer or mixing field is treated by distinct forcing functions introduced in the respective governing equations, thereby its presence is dealt with much easiness in the computational domain. This work proposes an extension of an IBM based on discrete forcing approach to simulate pressure driven electro-osmotic flow and mixing enhancement in constricted micro channels. The fractional-step based temporal discretisation and finite-volume basedspatial discretisation on a staggered mesh are used to solve the governing equations. Concentration forcing function is a parameter, which is newly defined in this model to satisfy the no-flux boundary condition for species concentration on the IB and is introduced in convection-diffusion equation. The present computational model is validated with the published experimental and numerical results in the literature and finally some sample results are also exemplified.