On the effect of the electrode shape and contraction section on the right-angled electromagnetic flowmeter

Abstract

Flow measurement is of great importance in many industries, such as the chemical industry, energy and urban drainage. Electromagnetic flowmeter is widely used due to its wide range, high response and suitability for multiphase flow detection. To meet the needs of small-caliber and low-flow applications and wider installation scenarios, this paper proposes a new insertion-type right-angled bent electromagnetic flowmeter. The measurement signal of the electromagnetic flowmeter is closely related to its internal fluid flow state, thus computational fluid dynamics (CFD) method is used to optimize the electrode shape and contraction section shape of the electromagnetic flowmeter. Through comparison experiments of flat electrodes and cone electrodes, a better model is obtained. Furthermore, three new models of the contraction section are proposed: the sharp contraction type, the gradual contraction type, and the Widosinski curve contraction section. The Widosinski curve contraction section is easier to stabilize the flow field inside the flowmeter. The experimental data are in good agreement with the results of the large eddy simulation, and the results show that the measurement performance of the cone electrode is better than that of the flat electrode. When measuring small flow rates, the error of the cone electrode is only 5%, much smaller than the error of the flat electrode. The findings of this study provide a new idea for the development and optimization of the measurement performance of the right-angled electromagnetic flowmeters.