Flow sensors for electrically conducting fluids based on the magnetic-inductive (MID) principle are widely used because they contain no moving parts. In the flowing fluid the Lorentz force, due to an outer magnetic field, separates electric charges and induces an electric field. The potential is proportional to the average flow velocity. In standard devices a tube with circular cross section is used. We propose a varying shape that can be adjusted such that the MID-effect is 50% larger. The concept is verified and optimized using Finite-Element-Simulations with Comsol Multiphysics. The 3-D simulations include Navier–Stokes equations for incompressible fluids, magnetostatics, and electrostatics. This paper features the design with 1 cm diameter in the flow range up to 6 m/s. The methodology, however, using Finite-Element-Analysis, that will be described here in detail, can be extended to other configurations.
Print ISSN: 0171-8096
Volume: 74, 06/2007
Pages: 374 - 379