Solids volume fraction of size-disperse dense granular flows

固体体积分数可能是描述颗粒材料的最基本的状态变量。在致密颗粒流中固体体积分数几乎是恒定的，但尽管如此，在设置其流变性方面起着至关重要的作用，随着体积分数达到临界值，粘度发散。对于单一尺寸的颗粒，这个临界体积分数是一个常数，但在一个以上的颗粒尺寸的混合物中，它随颗粒尺寸分布而变化。该项目的目的是开发描述颗粒尺寸分布，体积分数，流变学和分离率之间的众多相互作用和依赖关系的连续模型，其中许多是目前尚未探索的。实验室实验和离散元模拟相结合，将被用来验证新的连续模型的颗粒偏析和流动，其中固体体积分数演变的解决方案的一部分。该项目汇集了粒子技术，复杂流体和流变学以及连续介质力学的研究领域。

Solids volume fraction is perhaps the most fundamental state variable describing granular materials. The solids volume fraction is nearly constant in dense granular flows, but nonetheless plays a crucial role in setting their rheology, with the viscosity diverging as the volume fraction reaches a critical value. For grains of a single size this critical volume fraction is a constant, but in mixtures of more than one size of grain, it varies with the particle size distribution. The aim of this project is to develop continuum models that describe the numerous interactions and dependencies between particle size distribution, volume fraction, rheology and segregation rate, many of which are currently unexplored. A combination of laboratory experiments and discrete element simulations will be used to validate new continuum models for granular segregation and flow, in which the solids volume fraction evolves as part of the solution. The project brings together the research areas of particle technology, complex fluids and rheology, and continuum mechanics.