Two-dimensional electromagnetic induction equations have been solved for liquid metal flows in a large scale electromagnetic flowmeter taking account of both effects of the velocity profile and the wall conductivity.Theoretical solutions for the scalar potential, the induced current and the induced magnetic field have been obtained by adopting a fixed velocity function which approximates the overall turbulent flow profile.The distribution of the induced current density shows the eddy current loops, and the return currents exist mostly in the fluid region.The distribution of the induced magnetic field is presented under a condition of a high magnetic Reynolds number.The maximum induced magnetic field is evaluated to be about one order less than the value estimated by a classical method.The vector distribution of the electro-magnetic force due to the current and the induced magnetic field is also presented and we found the cancelling effect which prevents this force from becoming a predominant one.Through the analysis of the experiment, it is found the interaction parameter of 0.12 can identify the timing at which the skin friction factor (Cf) begins to increase.Also a discussion is made how the MHD effect will appear.
展开▼
