A self-developed experimental facility by the National Engineering Research Center of Novel Equipment for Polymer Processing, called a coaxial barrel dynamic rheometer, was used to test the predictability of the apparent viscosity equations of polymer melts in flat vibrating shear flows. The testing principle of the rheometer is to transform the shear power of a motor and extrusion pressure in a shear field to melt viscosity. The shear field can simulate an orthogonal superposed vibratory flow, boundary vibrating pressure flow, and their combined flow. By comparing equation predictions with experimental results, we show a qualitatively satisfactory and quantitatively reasonable predictive ability, which verifies the work of our mathematical derivations. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1560-1565, 2009