Liquid flow around a cylindrical MHD accelerator

Here you can see, thanks to coloured filaments, the flow induced by a cylindrical MHD accelerator plunged into acidulous water, electrically conductive. A rod magnet generates the axial magnetic field (towards the reader). In this example, it is a permanent magnet (1000 Gauss), thus the MHD efficiency is weak and the flow speed is moderate, but you can see the principle. The Lorentz force field creates a suction of the liquid upstream, and a laminar wake downstream, which is slightly disturbed by bubbles near the anode (gaseous emission from anodic oxidation, cause of electrolysis).

Digitized 16mm film, taken by Maurice Viton in 1976.