Image analysis of gas-phase corona discharge induced electrohydrodynamic liquid flow in stratified fluid observed by particle image velocimetry

Analysis of gas-phase needle-plate corona discharge induced electrohydrodynamic liquid flow in stratified fluid is carried out by image processing from the experimental results. In this paper, the flow velocity distribution is experimentally obtained by a particle image velocimetry with image processing, where the measurement system takes sequential digital images of flow field illuminated by a laser light sheet for computed tomography. The results show that the electrohydrodynamic induced fluid flow direction on an electrode axis is not from needle electrode to plate electrode axis when needle electrode position above liquid layer. For the case of the needle electrode tip immersed into the dielectric liquid, it is well known that the dielectric liquid makes anticlockwise rotation by contraries. Hence, new approaches are required for the analyses of the present type electrohydrodynamic fluid motion. The mechanistic model based on interfacial momentum transfer effects on liquid-phase fluid motion is discussed in detail.