Optimization of electroconvection over patterned membranes*

Electroconvection is a hydrodynamic instability that arises due to the bulk motion of ions driven by an applied electric field across an electrolyte. In applications such as electrodialysis desalination, this phenomenon leads to improved performance by promoting transport of ions towards an ion-selective membrane, where they are removed from the fluid. One method of controlling electroconvection is by geometrically manipulating the membrane surface via geometric patterning. We consider a specific type of patterning in which sections of the membrane are blocked, which has been shown to enhance transport rate (Davidson et al., Scientific Reports, 6, 22505, 2016). In this study, we utilize 2D direct numerical simulations of electroconvection, and present strategies for pattern optimization in order to maximize ion transport due to the pattern-induced flow.