Electrohydraulic power conversion in planar nanochannels.

We explore mechanisms for flow generation in water-filled nanochannels, employing the coupling between translational and rotational momentum. Using a generalized Navier-Stokes equation that includes dipolar polarization and relaxation, we show that static electric fields do not induce fluid flow in the planar geometry, while rotating electric fields efficiently convert electric into hydraulic power on the nanoscale. We also perform extensive molecular dynamics simulations of water in nanochannels and find that erroneous force truncation can give rise to spurious flow effects for static electric fields.