APS 2015 19-20 Agustus 2015, Bandung, Indonesia 1

Two-Dimension Granular Fission Toy Model and Evolution of Granular

Compaction

Sparisoma Viridi*, Rizal Kurniadi, and Abdul Waris

Nuclear Physics and Biophysics Research DivisionInstitut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia*dudung@gmail.com

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Outline

• Previous studies• Interactions• Molecular dynamics method• Simulation parameters• Results and discussion• Summaries

Previous study

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Viridi et al., AIP-CP 2012

Previous study (cont.)

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Viridi et al., JPFSM 2015

Interactions

• Repulsive force• Attractive force• Electrostatic force• Center force

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Interactions: Repulsive force

• Linear spring dash-pot model

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ijNijijNij vrkF ˆˆ

ijij rD ,0max

ijijijijij

ijij rrrr

rr

r

,ˆ

ijijijijij

ijij vvvv

vv

v

,ˆ

Interactions: Attractive force

• Gravitational-like force

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ijij

Gij rrmkG ˆ

2

2

Interactions: Electrostatic force

• Coulomb-like force

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ijij

jiQij rr

qqkQ ˆ

2

Interactions: Center force

• Near earth gravitation-like force

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ci

cigi rr

rrmkF

Molecular dynamics method

• Newton second law of motion

• Euler algorithm

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ijijijijii GQFF

ma

1

1

tatvttv

tvtrttr

Simulation parameters

• kN = 5×103, γN = 0

• kG = 0.5

• kQ = 1

• kg = 100, rc± =

• D = 0.5, m = 1, qi = 0

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)1,1(22

Simulation parameters (cont.)

• L = 2, 3, 4, 5

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Results and discussion

• Initial and final configurations• Evolution of compaction

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Initial and final config.. (L = 2)

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Initial and final config.. (L = 3)

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Initial and final config.. (L = 4)

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Initial and final config.. (L = 5)

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Evolution of compaction

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Summaries

• Considered forces and chosen parameters fission-like process for 2-d spherical granular configuration

• Compaction tends to form 2-d hexagonal close packed (HCP) system under influence of the forces

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Future plan

• Formulation to quantify compaction for multi-center compaction

• Introduce charged particles• Add probabilistic factor

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Acknowledgement

• This work is supported by Riset Inovasi Batch II with contract number 1763/I1.B04.1/KU/2015

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Thank you