A Lorentz force flowmeter is a noncontact electromagnetic flow-measuring device based on exposing a flowing electrically conducting liquid to a magnetic field and measuring the force acting on the magnet system. The m...A Lorentz force flowmeter is a noncontact electromagnetic flow-measuring device based on exposing a flowing electrically conducting liquid to a magnetic field and measuring the force acting on the magnet system. The measured Lorentz force is proportional to the flow rate via a calibration coefficient which depends on the velocity distribution and magnetic field in liquid. In this paper, the influence of different velocity profiles on the calibration coefficient is investigated by using numerical simulations. The Lorentz forces are computed for laminar flows in closed and open rectangular channels, and the results are compared with the simplified case of a solid conductor moving at a constant velocity. The numerical computations demonstrate that calibration coefficients for solid bodies are always higher than for liquid metals. Moreover, it can be found that for some parameters the solid-body calibration coefficient is almost twice as high as for a liquid metal. These differences are explained by analyzing the patterns of the induced eddy currents and the spatial distributions of the Lorentz force density. The result provides a first step for evaluating the influence of the laminar velocity profiles on the calibration function of a Lorentz force flowmeter.展开更多
Lorentz force velocimetry(LFV)is a noncontact technique for the measurement of velocities in hightemperature metal melts that is based on exposing the liquid metal to a magnetic field and measuring the force acting up...Lorentz force velocimetry(LFV)is a noncontact technique for the measurement of velocities in hightemperature metal melts that is based on exposing the liquid metal to a magnetic field and measuring the force acting upon the magnet system([1],[2],[3],[4]).The present communication provides an overview of recent research activities in LFV carried out at the Institute of Thermodynamics and Fluid Mechanics at Ilmenau University of Technology.The overview will focus on fundamental issues such as the suitability of LFV for local velocity measurement as well as on applications such as flow measurement in poorly conducting melts,industrial applications in aluminium production as well as on wet,dry and numerical calibration methods for LFV-systems.The present overview will be supplemented by individual presentations on specific topics to be presented in the papers by Heinicke,Jian,Wegfrass,Gramss,Kolesnikov and Karcher.展开更多
基金Project supported by the German Research Foundation(Deutsche Forschungsgemeinschaft)
文摘A Lorentz force flowmeter is a noncontact electromagnetic flow-measuring device based on exposing a flowing electrically conducting liquid to a magnetic field and measuring the force acting on the magnet system. The measured Lorentz force is proportional to the flow rate via a calibration coefficient which depends on the velocity distribution and magnetic field in liquid. In this paper, the influence of different velocity profiles on the calibration coefficient is investigated by using numerical simulations. The Lorentz forces are computed for laminar flows in closed and open rectangular channels, and the results are compared with the simplified case of a solid conductor moving at a constant velocity. The numerical computations demonstrate that calibration coefficients for solid bodies are always higher than for liquid metals. Moreover, it can be found that for some parameters the solid-body calibration coefficient is almost twice as high as for a liquid metal. These differences are explained by analyzing the patterns of the induced eddy currents and the spatial distributions of the Lorentz force density. The result provides a first step for evaluating the influence of the laminar velocity profiles on the calibration function of a Lorentz force flowmeter.
基金Item Sponsored by German Science Foundation (Deutsche Forschungsgemeinschaft) in the Framework of the Research Training Group (Graduiertenkolleg) "Lorentz Force Velocimetry and Lorentz Force Eddy Current Testing"at Ilmenau University of Technology
文摘Lorentz force velocimetry(LFV)is a noncontact technique for the measurement of velocities in hightemperature metal melts that is based on exposing the liquid metal to a magnetic field and measuring the force acting upon the magnet system([1],[2],[3],[4]).The present communication provides an overview of recent research activities in LFV carried out at the Institute of Thermodynamics and Fluid Mechanics at Ilmenau University of Technology.The overview will focus on fundamental issues such as the suitability of LFV for local velocity measurement as well as on applications such as flow measurement in poorly conducting melts,industrial applications in aluminium production as well as on wet,dry and numerical calibration methods for LFV-systems.The present overview will be supplemented by individual presentations on specific topics to be presented in the papers by Heinicke,Jian,Wegfrass,Gramss,Kolesnikov and Karcher.
