Energy transfer through streaming effects in time-periodic pressure-driven nanochannel flows with interfacial slip

Abstract

We analytically investigate the prospect of using electrokinetic phenomena to transfer hydrostatic energy to electrical power with high energy transfer efficiencies, by exploiting time periodic pressure-driven flows in narrow fluidic confinements. An expression for the energy transfer efficiency for such pulsating pressure-driven flows is derived by considering wall-slip effects due to hydrophobic interactions, strong electrical double layer interactions in the confined flow passages, possibilities of exploring the regimes of large wall potentials, and the adverse consequences of the finite conductance of the Stern layer. It is revealed from our studies that high-frequency pressure pulsations may be employed in practice to improve the concerned energy transfer efficiency to a considerable extent, instead of using a steady-state pressure field. Such favorable effects are found to be best exploited by utilizing “slipping” electro-hydrodynamics in thick electrical double layers in the presence of high surface potentials.