Abstract
Large eddy simulation (LES) is conducted to reveal turbulent phenomena in a liquid metal MHD generator with a square duct to which a non-uniform magnetic field is applied. The applied magnetic field suppresses the turbulence even in the downstream without the magnetic field. In the downstream, the central velocity is decelerated, so that an M-shaped velocity profile is observed as well as turbulence structures like a Karman vortex. Two streamwise gradients of the applied magnetic field bring out the twin eddy currents. It is found that a subgrid model based on the turbulence structure gives an appropriate representation of the laminarization unlike Smagorinsky model.
