Linear viscoelastic analysis using frequency-domain algorithm on oscillating circular shear flows for bubble suspensions

• Published in: Rheologica acta Vol. 57; no. 3; pp. 229 - 240
• Main Authors: Tasaka, Yuji, Yoshida, Taiki, Rapberger, Richard, Murai, Yuichi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2018; Springer Nature B.V
• Subjects: Algorithms; Aqueous solutions; Bubbles; Characterization and Evaluation of Materials; Chemistry and Materials Science; Complex Fluids and Microfluidics; Deformation; Elasticity; Equations of motion; Food Science; Frequency analysis; Frequency domain analysis; Materials Science; Mechanical Engineering; Momentum transfer; Newtonian fluids; Noise measurement; Noise propagation; Original Contribution; Polymer Sciences; Rheological properties; Rheology; Rheometers; Rheometry; Shear thinning (liquids); Soft and Granular Matter; Velocity distribution; Viscoelastic fluids; Viscoelasticity; Bubble suspensions; Ultrasonic velocimetry; Linear viscoelasticity; Rheometry
• ISSN: 0035-4511; 1435-1528
• DOI: 10.1007/s00397-018-1074-z

To achieve a stable evaluation of the linear viscoelasticity of bubble suspensions, which have difficulties for conventional rheometers from spatial distributions of rheological properties with bubble deformations, we proposed a novel rheometry based on spatio-temporal velocity data obtained by ultrasonic velocity profiling (UVP). A frequency-domain algorithm was adopted to overcome a critical influence of measurement noise on the rheological assessment, which is inferred from error propagation characteristics through the equations of motion in discretized form. Applicability and advantage of the present rheometry with the frequency-domain algorithm were verified by two kinds of fluids: high viscous oil as a Newtonian fluid and polyacrylamide aqueous solution as a shear thinning, viscoelastic fluid. The rheometry was finally adopted for bubble suspensions subject to high oscillatory shear, and it could validly extract elasticity-originated momentum transfer as a function of space.