Abstract
Results of thermal noise measurements (frequency range 0.01–1000 Hz) on aqueous solutions of poly(ethylene oxide) and maltose/poly(acrylamide) during capillary flow are reported. The flow of these solutions, both being of the pseudoplastic (shear thinning) type, gave rise to an excess thermal noise exhibiting a 1/fα-frequency distribution. The excess noise level increased with the flow rate. At a critical value of this rate, the noise showed a pulsating character. The corresponding frequency spectra contained a number of sharp peaks, all being multiples of a fundamental frequency of the order of 1 Hz. Increasing the flow rate still higher caused the pulsations to disappear, the excess noise regaining its 1/fα character. The pulsations appear to be associated with the elasticity of the solutions used. Solutions with comparable shear thinning properties but lacking elasticity did not produce such effects. No excess thermal noise was observed with Newtonian solutions of comparable viscosity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
