Magnetoconvection in an electrically conductive duct flow
Mixed convection of an electrically conductive fluid in a square duct with imposed transverse magnetic field is studied using Large Eddy Simulation (LES) paradigms. The duct walls are electrically conductive, with the wall conductivity parameter cw ranging from 0 to 0.5. The Reynolds number is Re = 5602 and the Prandtl number is Pr = 0.0238. The focus of the study is on flows at Hartmann numbers Ha ⩽ 125, Richardson numbers Ri ⩽ 10 and two different thermal boundary are considered: uniform heat fluxes and one-sided heating. The results show that the transition from laminar to turbulent flow depends not only on the ratio Ri/Ha, but also to cw and to the local thermal boundary conditions. In the turbulent regime with one-sided heating, the turbulent heat fluxes play an important role in the total heat transfer, in contrast with the typical behavior of liquid metals. It is also found that large values of cw tend to impair the turbulent heat fluxes.