Flow Velocity Distribution Downstream of Nanofibrous Filter in Minichannel Determined by Particle Image Velocimetry Method

The paper presents the results of investigations of flow velocity field distribution downstream of the nanofibrous filter in a minichannel determined by the particle image velocimetry (PIV) method. The nonwoven nanofibrous filter was produced by electrospinning technology from a PVDF polymer dissolved in DMAC and acetone mixture. The nanofibers were deposited onto a mesh scaffold made of stainless steel wires 0.2 mm in diameter and with a 2 mm pitch. The gas velocity in the channel with the inserted nanofibrous filter was below 1.2 m/s. The flow field distribution in the channel was investigated by the Dantec FlowMap System. It was shown that the turbulence can be generated downstream of the filter, even for low Reynolds numbers smaller than 1300. This turbulence was attributed to the inhomogeneity of the fibrous filter structure. Another cause of this phenomenon could be the large area of the boundary layer at the channel walls compared to the channel cross section.