A new scanning slit rheometer for electro-rheological fluids

Abstract

A new scanning slit rheometer is presented for the rheological property measurement of electro-rheological (ER) fluids with Bingham-plastic model, based on a single measurement of liquid height variation with respect to time. The apparatus consisting mainly of an overhead reservoir, an ER slit, connecting and rising tubes, and a video camera connected to a computer is described with an experimental procedure. The present method overcomes one of the major drawbacks of the conventional viscometer, the inability to produce the yield stress of the ER fluid in an absolute zero shear rate range. The results with the present rheometer are compared with those obtained from a commercially available rheometer, indicating an excellent agreement. © 2000 American Institute of Physics.