Towards replacing physical testing of granular materials with a Topology-based Model

Area of Science:

• Materials Science
• Fluid Dynamics
• Computational Physics

Background:

• Effective surface area measurement in granular materials is crucial for predicting performance, often using the Carman-Kozeny equation.
• The Carman-Kozeny equation relies on assumptions about pore structure that are inaccurate for materials with diverse particle shapes and sizes.
• Powdered systems with wide particle size and shape distributions present challenges for traditional surface area measurement techniques.

Purpose of the Study:

• To develop a more accurate method for determining the effective surface area of packed granular materials.
• To overcome the limitations of the Carman-Kozeny equation in complex particle systems.
• To introduce a virtual measurement technique using micro-CT imaging and a novel pore network model.

Main Methods:

• Utilized micro-CT imaging to create virtual representations of powdered materials.
• Developed a new Pore Network Model based on the Morse-Smale complex skeleton to identify pores and their connections.
• Computed fluid flow and conductivity within the pore structure by solving a resistive network model.
• Estimated flow-permeable surface area through direct conductivity computation and by analyzing flow dead-ends.

Main Results:

• The new pore network model provides a robust framework for analyzing fluid flow in granular materials.
• Two distinct methods for estimating flow-permeable surface area were established, offering consistency across varied material properties.
• The virtual approach demonstrated potential for accurate characterization beyond the assumptions of the Carman-Kozeny equation.

Conclusions:

• The developed Pore Network Model offers a superior alternative to the Carman-Kozeny equation for effective surface area determination in complex granular systems.
• This virtual methodology enables accurate fluid flow and surface area analysis for diverse powdered materials.
• The findings have significant implications for industries utilizing powdered materials where precise characterization is essential.