CFD-DEM simulation of air-assisted electrospinning

This study presents a new modeling approach to simulate formation of polymeric fibers via the air-assisted electrospinning process. In this model, the aerodynamic and electrostatic fields were simulated using the techniques of computational fluid dynamics (CFD), implemented in COMSOL software package, and the fiber formation process was modeled using an in-house quasi 1-D discrete element method (DEM) code. Our CFDDEM simulations were calibrated for Polystyrene (PS) and Polyurethane (PU) and their predictions were compared with experiments. We studied the influence of coaxial airflow on the fiber formation and fiber deposition pattern. In agreement with experiments, our simulations revealed that increasing the velocity of the sheath air decreases the diameter of the resulting fiber, due perhaps to the accelerated solvent evaporation. Moreover, the addition of the airflow seemed to reduce the whipping instability of the fiber, resulting in a more focused fiber deposition pattern. The computational approach developed in this work can serve as a design and optimization tool for air-assisted electrospinning process.