3D Computational Modeling of Bubble Removal in a Microfluidic System Consisting of a T-junction and Nanofibrous Membranes

In this research work, a 3D computational fluid dynamics (CFD) model is developed to simulate the bubble generation and its removal from a microfluidics system. This bubble removal system uses a well-known T-junction configuration to generate gas bubbles within a water-filled microchannel. The gas bubbles are later removed using a hydrophobic nanofibrous membrane and a bubble trap cavity. The model is used to study the effects of various geometrical and flow parameters on bubble removal capability of the system. The results indicate that the maximum gas bubble removal rate decreases with increasing the water flow rate. The effects of cavity size and channel width on bubble removal are also investigated. It is shown that any geometry that increases the bubble residence time inside the cavity, will increase the bubble removal capacity. It is demonstrated that the offset configuration for the cavity inlet and outlet channels has a better bubble removal capability than the in-line configuration. In addition, a series of experiments are preformed to verify the numerical results. Computational results are found to be in a good agreement with the experimental data. Furthermore, the behavior of two-phase flow for both the complete and partial bubble removal cases is described detail.