Simulation of meltblown processes - parameter study for polymer temperature and viscosity

In meltblown processes, microfibers and nanofibers are produced by the extrusion of polymeric jets into a directed, turbulent high-speed airflow. Due to its complexity direct numerical simulations of the multiscale-multiphase process are not possible. Fraunhofer ITWM developed a numerical framework for a forming fiber in turbulent air that makes the simulation of industrial setups feasible. For this purpose, an asymptotic viscoelastic model for the fiber is employed. The turbulent effects are taken into account by a stochastic aerodynamic force model where the underlying velocity fluctuations are reconstructed from a turbulence characterization of the airflow. A parameter study is performed, where the results clearly show how different parameters influence the fiber diameter distribution in the final product.