|Abstract: ||A method and apparatus for determining a property of a fluid in a vessel.
The method uses magnetic tracer particles and an externally applied
magnetic field which orients the particles. When the fluid moves, it
changes the orientation of the tracer particles, thus changing the
magnetic fields. These changes are detected by external magnetic field
sensors. By using mathematical models, the property of the fluid in the
vessel is determined from the detected magnetic field. In this manner,
fluid vorticity, velocity, strain and stress may be estimated.