Discernment of non-Newtonian behavior in liquids by acoustic means

An experiment was conducted with the use of a "sonic viscometer" to demonst rate that a change in the constitutive nature of a fluid will alter the ove rtones that occur from the nonlinearity of the propagation of a sine wave t hrough the fluid. Pure sine waves ranging octave-wise from 500 to 8000 Hz w ere introduced into distilled water, and FFT analyses of the signals receiv ed were compared with those resulting from transmission of the same set of sine waves through a 1% solution of polyethylene oxide in distilled water. Differences in the FFT spectra which occur as the result of introducing the polymeric solute indicate that the device could prove viable in indicating small changes in viscous properties.