Development of a Kármán Vortex Probe for Measuring the Velocity of Molten Metal Flow

Abstract

A new probe was developed for measuring the velocity of molten metal flows at high temperatures. This probe consists of a circular cylinder, its supporting rod, and a frequency detection unit. The principle of velocity measurement by means of the present Kármán vortex probe is as follows. When the cylinder is immersed in a flow field, very regular patterns, called Kármán’s vortex streets, are formed behind the cylinder. The shedding frequency of the Kármán vortices is proportional to the velocity of the flow approaching the cylinder, and hence the velocity can be determined by detecting the shedding frequency. Its applicability to molten metal flows was confirmed using molten Wood’s metal. It should, however, be stressed that this probe is essentially applicable to one-dimensional flows near the bath surface in metallurgical reactors.