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29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 1
Granular buoyant force in a
two-dimensional intruder-
particles bed system
Dewi Muliyati1
, Nurhayati2
, Johri Sabaryati3
, Sparisoma Viridi4
1
FMIPA, Universitas Negeri Jakarta, Jakarta 13220, Indonesia
2
FST, Universitas Islam Negeri Ar-Raniry, Banda Aceh 23111, Indonesia
3
FKIP, Universitas Muhammadiyah Mataram, Mataram 83127, Indonesi
4
FMIPA, Institut Teknologi Bandung, Bandung 40132, Indonesia
1
dmuliyati@gmail.com, 2
firstnur1708@gmail.com, 3
joyafarashy@gmail.com, 4
dudung@gmail.com,
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 2
Outline
• Introduction
• Theory
• Simulation
• Results and discussion
• Conclusion
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 3
Introduction
Buoyancy
• It is an interesting phenomenon, especially if
not only involving fluid and object densities as
reported in 1873
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 4
G. Sigerson, "On a Cause of the Buoyancy of Bodies of a Greater Density than Water", Proceedings of the Royal Irish
Academy. Science, vol. 2 (1875 - 1877), pp. 22-25, June 1873, url https://www.jstor.org/stable/20489980
Automatic observation
• Today buoyancy can be ob-
served using microcontroller
that au-
toma-
tically
mea-
sures
the data
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 5
P. R. Espindola, C. R. Cena, D. C. B. Alves, D. F. Bozano, A. M. B. Goncalves, "Use of an Arduino to studybuoyancy
force", Physics Education, vol. 53, no. 3, p. 035010, May 2018, url https://doi.org/10.1088/1361-6552/aaa93a
Virtual laboratory
• The phenomenon is still interesting to investi-
gate through a virtual laboratory
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 6
J. M. Vitale, M. C. Linn, "Designing Virtual Laboratories to Foster Knowledge Integration: Buoyancy and Density", in M.
E. Auer et al. (eds.), Cyber-Physical Laboratories in Engineeringand Science Education, chap. 7, pp. 163-189, 2018,
url https://doi.org/10.1007/978-3-319-76935-6_7
Graphical concept
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 7
J. M. Vitale, L. Applebaum, M. C. Linn, "Coordinatingbetween Graphs and Science Concepts: Density and Buoyancy",
Cognition and Instruction, vol. 37, no. 1, pp. 38-72, Jan 2019, url https://doi.org/10.1080/07370008.2018.1539736
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 8
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 9
Theory
Buoyant force
• Object i with immersed volume Vi' in fluid
with density ρf in environment with gravity ,
will have buoyant force of
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 10
.
gVB ifi

′−= ρ
g

Gravitational force
• Object i with volume Vi with density ρg in
environment with gravity , will have
gravitational force of
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 11
.
g

gVG igi

ρ=
Newton’s 1st
law of motion
• In equilibrium for object i
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 12
.
( )
ifig
ifig
ifig
ifig
ii
i
VV
VV
gVV
gVgV
BG
F
′=
=′−⇒
=′−
=′−
=+
=∑
ρρ
ρρ
ρρ
ρρ
0
0
0
0
0




′i
h ih
A
AhV =
gρfρ
iB

iG

29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 13
Simulation
Normal forces
• Spherical grains i will have normal force from
spherical grains j in the form of
with
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 14
.
ijijNijijNij vrkN ˆˆ ξγξ −=

( )ijjiij rRR −+= ,0maxξ
The other forces
• Grains i will under influence of following
forces
– Buoyant force (slide 10)
– Gravitational force (slide 11)
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 15
Molecular dynamics method
• Newton 2nd
law of motion
• Forward finite difference
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 16








++=⇒= ∑∑ j
ijii
i
iii NGB
m
aamF
 1
( ) ( ) tatvdttv ∆+=+

( ) ( ) ( ) ttvtrdttr ∆+=+

29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 17
Results and discussion
Stage 1: "Fluid" condensation
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 18
.
Stage 2: Object intruding
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 19
Stage 3: System equilibrium
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 20
Some final states
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 21
ρi / ρf = 2/2 ρi / ρf = 3/2 ρi / ρf = 4/2 ρi / ρf = 5/2
ρi / ρf = 6/2 ρi / ρf = 7/2 ρi / ρf = 8/2 ρi / ρf = 9/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 22
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 2/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 23
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 3/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 24
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 4/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 25
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 5/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 26
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 6/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 27
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 7/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 28
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 8/2
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 29
0
0.04
0.08
0.12
0.16
0.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
z
t
ziavg
zbmax
zbavg
ρi / ρf = 9/2
Code
• Part of butiran.js
https://github.com/dudung/butiran.js
• Application
https://rawcdn.githack.com/dudung/butiran.j
s/f85fd1334dfd4d95a28ea2b254134f7603c6b
7d8/app/igdensity/igdensity.html
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 30
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 31
Conclusion
Conclusion
• Molecular dynamics-based simulation for
investigating density from particles point of
view has been built (based on butiran.js)
• Final state is similar to macroscopic system if
(individual particle) object density larger than
(individual particle) fluid density, ρi / ρf ≥ 4/2
• Compaction of all particles will prevent further
equilibrium
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 32
Acknowledgments
• Author would like to thank to SNF Committee
and FMIPA UNJ for the honour as invited
speaker in parallel session
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 33
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 34
https://osf.io/4umtr/
29 Juni 2019
Jakarta, Indonesia
SNF-UNJ 2019 35
Thank you

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Granular buoyant force in a two-dimensional intruder-particles bed system

  • 1. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 1 Granular buoyant force in a two-dimensional intruder- particles bed system Dewi Muliyati1 , Nurhayati2 , Johri Sabaryati3 , Sparisoma Viridi4 1 FMIPA, Universitas Negeri Jakarta, Jakarta 13220, Indonesia 2 FST, Universitas Islam Negeri Ar-Raniry, Banda Aceh 23111, Indonesia 3 FKIP, Universitas Muhammadiyah Mataram, Mataram 83127, Indonesi 4 FMIPA, Institut Teknologi Bandung, Bandung 40132, Indonesia 1 dmuliyati@gmail.com, 2 firstnur1708@gmail.com, 3 joyafarashy@gmail.com, 4 dudung@gmail.com,
  • 2. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 2 Outline • Introduction • Theory • Simulation • Results and discussion • Conclusion
  • 3. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 3 Introduction
  • 4. Buoyancy • It is an interesting phenomenon, especially if not only involving fluid and object densities as reported in 1873 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 4 G. Sigerson, "On a Cause of the Buoyancy of Bodies of a Greater Density than Water", Proceedings of the Royal Irish Academy. Science, vol. 2 (1875 - 1877), pp. 22-25, June 1873, url https://www.jstor.org/stable/20489980
  • 5. Automatic observation • Today buoyancy can be ob- served using microcontroller that au- toma- tically mea- sures the data 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 5 P. R. Espindola, C. R. Cena, D. C. B. Alves, D. F. Bozano, A. M. B. Goncalves, "Use of an Arduino to studybuoyancy force", Physics Education, vol. 53, no. 3, p. 035010, May 2018, url https://doi.org/10.1088/1361-6552/aaa93a
  • 6. Virtual laboratory • The phenomenon is still interesting to investi- gate through a virtual laboratory 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 6 J. M. Vitale, M. C. Linn, "Designing Virtual Laboratories to Foster Knowledge Integration: Buoyancy and Density", in M. E. Auer et al. (eds.), Cyber-Physical Laboratories in Engineeringand Science Education, chap. 7, pp. 163-189, 2018, url https://doi.org/10.1007/978-3-319-76935-6_7
  • 7. Graphical concept 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 7 J. M. Vitale, L. Applebaum, M. C. Linn, "Coordinatingbetween Graphs and Science Concepts: Density and Buoyancy", Cognition and Instruction, vol. 37, no. 1, pp. 38-72, Jan 2019, url https://doi.org/10.1080/07370008.2018.1539736
  • 8. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 8
  • 9. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 9 Theory
  • 10. Buoyant force • Object i with immersed volume Vi' in fluid with density ρf in environment with gravity , will have buoyant force of 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 10 . gVB ifi  ′−= ρ g 
  • 11. Gravitational force • Object i with volume Vi with density ρg in environment with gravity , will have gravitational force of 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 11 . g  gVG igi  ρ=
  • 12. Newton’s 1st law of motion • In equilibrium for object i 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 12 . ( ) ifig ifig ifig ifig ii i VV VV gVV gVgV BG F ′= =′−⇒ =′− =′− =+ =∑ ρρ ρρ ρρ ρρ 0 0 0 0 0     ′i h ih A AhV = gρfρ iB  iG 
  • 13. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 13 Simulation
  • 14. Normal forces • Spherical grains i will have normal force from spherical grains j in the form of with 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 14 . ijijNijijNij vrkN ˆˆ ξγξ −=  ( )ijjiij rRR −+= ,0maxξ
  • 15. The other forces • Grains i will under influence of following forces – Buoyant force (slide 10) – Gravitational force (slide 11) 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 15
  • 16. Molecular dynamics method • Newton 2nd law of motion • Forward finite difference 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 16         ++=⇒= ∑∑ j ijii i iii NGB m aamF  1 ( ) ( ) tatvdttv ∆+=+  ( ) ( ) ( ) ttvtrdttr ∆+=+ 
  • 17. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 17 Results and discussion
  • 18. Stage 1: "Fluid" condensation 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 18 .
  • 19. Stage 2: Object intruding 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 19
  • 20. Stage 3: System equilibrium 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 20
  • 21. Some final states 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 21 ρi / ρf = 2/2 ρi / ρf = 3/2 ρi / ρf = 4/2 ρi / ρf = 5/2 ρi / ρf = 6/2 ρi / ρf = 7/2 ρi / ρf = 8/2 ρi / ρf = 9/2
  • 22. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 22 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 2/2
  • 23. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 23 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 3/2
  • 24. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 24 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 4/2
  • 25. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 25 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 5/2
  • 26. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 26 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 6/2
  • 27. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 27 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 7/2
  • 28. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 28 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 8/2
  • 29. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 29 0 0.04 0.08 0.12 0.16 0.2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 z t ziavg zbmax zbavg ρi / ρf = 9/2
  • 30. Code • Part of butiran.js https://github.com/dudung/butiran.js • Application https://rawcdn.githack.com/dudung/butiran.j s/f85fd1334dfd4d95a28ea2b254134f7603c6b 7d8/app/igdensity/igdensity.html 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 30
  • 31. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 31 Conclusion
  • 32. Conclusion • Molecular dynamics-based simulation for investigating density from particles point of view has been built (based on butiran.js) • Final state is similar to macroscopic system if (individual particle) object density larger than (individual particle) fluid density, ρi / ρf ≥ 4/2 • Compaction of all particles will prevent further equilibrium 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 32
  • 33. Acknowledgments • Author would like to thank to SNF Committee and FMIPA UNJ for the honour as invited speaker in parallel session 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 33
  • 34. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 34 https://osf.io/4umtr/
  • 35. 29 Juni 2019 Jakarta, Indonesia SNF-UNJ 2019 35 Thank you