(152d) Calculation of fundamental dense granular flow

Granular flow has characteristics which differ markedly from fluid flow. The difference in character between a fluid and granular material is obvious when watching spilled milk roll off a table while spilled sugar forms a pile. A calculation method which captures the physics of granular flow is presented with emphasis on demonstrating accurate predictions of the fundamental nature of granular flow. Solutions to three problems are presented: settling of particles to close pack, hopper flow (hour glass), and particle flow in a U-tube. These granular flows exhibit behavior not predicted by fluid flow. Because the transient problems are ?simple? and are solved to completion (stagnant state), the true granular behavior cannot be masked by complex geometry and boundary conditions. All calculations are three-dimensional, and the results are compared to analytic solutions and measured data. The simple problems give confidence in the calculation method, but the need is to predict industrial granular flow problems. With accurate calculation of fundamental granular flow, the leap-of-faith is made that predictions of granular flow in complex full-scale hardware will also be accurate. As a commercial example, the transient, three-dimensional particle distribution from a three-dimensional calculation of a full-size riser is given.