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

GRANULAR CHUTE FLOW WITH TWO TURNINGS:

FLOWING BEHAVIOR AND ITS OPTIMIZATION

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 )

[email protected]

Contents 1. Motivations

2. Experiment Setup

3. Flowing Behavior

4. Simulation

5. Optimization Discussions

MOTIVATIONS

1.Motivations: Landslides

Bio-systems (bottleneck & bending)

Blood CellMolecule Motor

Bottlenecks in Coal Pipelines

Bending Merging & Width Decrease

Traffic Flow & Pedestrian Flow

EXPERIMENT

Experiment Setup

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).

Bi-Stable Phenomenon

Initial Condition Dependence

High Initial Flux

Dilute FlowDense

Dilute

Low Initial Flux

Dilute

Dense

Dense Flow

Dense

Initial Flux depends on Packing

Loose pack Crystal pack

Huang D, Sun G, Lu K, Phys. Rev. E 74, 061306 (2006). c

Flux – Width Relation

EffectiveWidthIncrease

StableHeap

Stable Heap

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

SIMULATION

Jin

Dilute –Dense transition condition for turning A

Jout

c

v

v

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

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