Airflow characterization within the pleat channel of HEPA filters with mini pleats

High efficiency particulate air (HEPA) pleated filters are used to ensure the containment of airborne contamination within nuclear facilities. These filters are often the last barrier before a potential release of radioactive substances into the environment. The present article focuses on the characterization of air velocity fields within mini-pleats HEPA filters at the elementary pleat scale. Numerical simulations of the velocity fields in a pleat using two different codes, ANSYS CFX and GeoDict, based on two different simulation strategies have been performed. Computed velocity profiles within the pleat have then been compared to measurements performed using an experimental setup based on a mu-PIV measurement technique. Results show that both codes are able to reproduce the measured profiles with a satisfying accuracy. However, GeoDict requires a much finer meshing than ANSYS CFX because the voxel size is constant for the whole domain. Simulation and experimental results confirm a self-similarity profile along the pleat assessed as a hypothesis by other authors working on this topic.