Paper Number
DP6                         My Program 

Session
Dense Particulate Systems

Title
Flow transitions and effective properties in multiphase Taylor–Couette flow

Presentation Date and Time
October 14, 2024 (Monday) 3:45

Track / Room
Track 3 / Waterloo 5

Authors (Click on name to view author profile)

1. Shetty, Abhishek (Anton Paar, Rheology)
2. Hunt, Melany (California Institute of Technology, Division of Engineering and Applied Science)
3. Young, Arthur (Harvard University, Harvard Paulson School of Engineering and Applied Sciences)

Author and Affiliation Lines (in printed abstract book)
Abhishek Shetty¹, Melany Hunt² and Arthur Young^3
1Rheology, Anton Paar, Ashland, VA 23005; ²Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA; ³Harvard Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA

Speaker / Presenter 
Shetty, Abhishek

Keywords
experimental methods; dense systems; flow-induced instabilities; non-Newtonian fluids; particualte systems; suspensions

Text of Abstract
The properties of multiphase flows are challenging to measure, and yet effective properties are fundamental to modelling and predicting flow behaviour found throughout many geophysical and industrially relevant flows. In the present work, an air bearing rheometer coupled with a powder flow cell is used to carry out a careful exploration of a gas-fluidized bed in which the fluidization rate and the rotational speed can be varied independently. The measured torque displays a range of rheological states: quasistatic, dense granular flow behaviour at low fluidization rates and low-to-moderate shear rates; turbulent toroidal-vortex flow at high shear rates and moderate-to-high fluidization rates; and viscous-like behaviour with rate-dependent torque at high shear rates and low fluidization or at low shear rates and high fluidization [1].To understand the solid-like to fluid-like transitions, additional experiments were performed in the same rheometer using single-phase liquid and liquid–solid suspensions.The results further demonstrate that these different multiphase flows undergo analogous flow transitions at similar Bingham or Reynolds numbers once effective properties are computed which allows one to compare the results across all the experiments.The corresponding dimensionless torques associated with these experiments also show comparable scaling in response to annular shear. References [1] Young, A. B., Shetty, A., & Hunt, M. L. (2024). Flow transitions and effective properties in multiphase Taylor–Couette flow. Journal of Fluid Mechanics, 983, A14.