Applications of Real-Time Radiography to Rheological Characterization and Processing Dynamics.

摘要

The combination of real-time radiography, high-speed video recording, and image analysis is used to study the internal dynamics of concentrated suspensions. This technique is used to measure macroscopic rheological properties and to obtain information about the microstructure of highly concentrated suspensions. By measuring the average velocity of a sphere falling through the suspension, the macroscopic viscosity is determined. The fluctuations about the mean velocity have been shown to be more sensitive to microstructural information, such as differences in the shapes and sizes of the suspended particles, the overall volume fraction of the dispersed phase, and particle aggregation. In addition, this technique has been used to observe mass settling of nonneutrally buoyant particles in highly concentrated suspensions. We find that group settling velocities can be over an order of magnitude faster than individual settling velocities. In addition, this technique may be used to follow tracer particles during the processing of highly filled particulate systems. (ERA citation 13:001490)