| Filtration technology has found extensive applications in a variety of industries such as oil and gas, aerospace, automotive, agriculture, food processing and pharmaceutical industries. While numerous experimental approaches have been used to optimize the filtration performance, modeling approach is playing an increasingly important role in filtration research as a complimentary tool to experiments. In gas-liquid filtration, a coalescing filter medium is installed in a holder placed in the middle of a long pipe in which the aerosol mixed gas flow passes through porous medium to get purified with aid of filter. Modeling the whole process requires the development of a coupled flow model that describe the flow dynamics in both free channel and porous media flow domain. A flexible finite element method using FlexPDE(TM); software was applied to simulate the flow field such as velocity and pressure profile in the full coupled flow domain including the interface between free channel and porous media. Multiphase transport theory was introduced to set up property balance equations to model the species balance for different types of substances in gas and liquid phase.;In this research, a feasible and effective approach has been proposed to model coupled free channel and porous medium flows over a wide range of permeabilities. In further study, a dynamic simulation of spatial and temporal transport phenomenon of aerosols through free channel and filter medium was developed on the basis of coupled flow model to describe the start-up and loading stage of gas-liquid filtration. A series of parametric study were carried out to evaluate the influence of a variety of factors on filtration performance. Modeling of coalescence phenomenon was also investigated and some preliminary results showed a replication of 'U' shape saturation profile during filtration process. This work contributes to a better understanding of coalescing filtration in terms of flow dynamics for different species, time-dependent saturation profile and mechanism of drop coalescence.;Another application of FlexPDE simulation assisted in a precise and controlled production of electrospun nanofibers by modeling the 3 dimensional electrostatic field to forecast the trajectory of electrospinning jets. The model predictions achieved a good agreement with experimental results, demonstrating an effective computational approach to improve the production efficiency in electrospinning process. |
