granular Chute flow with Two turnings : Flowing behavior and Its optimization

1. Mao-Bin HU (胡茂彬), G.C. Yang(杨果成), Q.Y. Liu(刘启一), R. Jiang (姜锐), Q.S. Wu(吴清松) humaobin@ustc.edu.cn granular Chute flow with Two turnings:Flowing behavior and Its optimization

2. Contents • 1. Motivations • 2. Experiment Setup • 3. Flowing Behavior • 4. Simulation • 5. Optimization Discussions

3. Motivations

4. 1.Motivations: Landslides

5. Bio-systems (bottleneck & bending) Molecule Motor Blood Cell

6. Bottlenecks in Coal Pipelines Merging & Width Decrease Bending

7. Traffic Flow & Pedestrian Flow

8. Experiment

9. Experiment Setup

10. Dilute - Dense flow transition K. To, P.-Y. Lai, H. K. Pak, Phys. Rev. Lett. 86, 71 (2001). M. Hou, K. Lu, C.K. Chan, Phys. Rev. Lett.91, 204301 (2003).

11. Bi-Stable Phenomenon

12. Initial Condition Dependence Dilute Dense Dense Dilute Flow Dense Flow Dilute Dense High Initial Flux Low Initial Flux

13. Initial Flux depends on Packing Crystal pack Loose pack Huang D, Sun G, Lu K, Phys. Rev. E 74, 061306 (2006). c

14. Flux – Width Relation

15. Effective Width Increase Stable Heap

17. Stable Heap N. Taberlet, etal, Phys. Rev. Lett. 91, 264301 (2003).

18. Simulation

19. Dilute –Dense transition condition for turning A c Jin Jout

20. v v

22. Optimization Discussions • 1. Adjust the main section width below the dilute-dense transition point • 2. Watch that no stable heap can develop in the main section • 3. In the bi-stable region, get a higher initial flux • 4. Increase outlet width D2, so that only turning A plays the role of bottleneck

23. Thank you !