Complexity in granular materials and porous media: More is - PowerPoint PPT Presentation

Complexity in granular materials and porous media: “More is Different” by Marcel Moura and Gaute Linga marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Complexity in granular materials and porous media: “More is Different” by Marcel Moura and Gaute Linga marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Van Gogh – Wheatfield with Crows (1890) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

COMPLEXITY ARISES! marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Reductionism ---------- Constructivism “More is Different”, by Philip W. Anderson. Science , Vol. 177, No. 4047 (1972) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

All that is fundamentally important? Reductionism is an important concept: explanation in terms of simpler, smaller entites. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

COMPLEXITY ARISES! marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Indeed, reductionism is an important concept … … yet, reductionism does NOT imply constructivism. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Granular materials : a complex system • Second-most manipulated material in industry (first one is water). • Essential for construction, pharmaceutical industry, oil industry, food industry… • Extremely challenging: studied for centuries, still waiting for a complete theoretical description. • Presents a wide range of interesting phenomena: force networks, Reynolds dilation, spontaneous stratification, etc. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Hydrostatic pressure increases linearly in a regular fluid in equillibrium But not in a granular material! Bi et al, Nature 480 , 355 (2011) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Plastic ruler through polarizing filter. https://www.youtube.com/watch?v=IdJLP0BNOt4 https://www.vitensenteret.com/en/mod377e marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Fun for quarantined physicists: try it at home! If you don’t have a polarizer in your pocket (you should always have a polarizer in your pocket), you can use polarized sunglasses. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Fun for quarantined physicists: try it at home! If you don’t have a polarizer in your pocket (you should always have a polarizer in your pocket), you can use polarized sunglasses. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Fun for quarantined physicists: try it at home! If you don’t have a polarizer in your pocket (you should always have a polarizer in your pocket), you can use polarized sunglasses. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Fun for quarantined physicists: try it at home! If you don’t have a polarizer in your pocket (you should always have a polarizer in your pocket), you can use polarized sunglasses. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers S. Lherminier et al., Phys. Rev. Lett. 113 , 098001 (2014) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers N. Iikawa et al., Phys. Rev. Lett., 116, 128001 (2016) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers R. Planet et al., Mimicking earthquakes with granular media , Proceedings CFM 2015 marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Credit: Osvanny Ramos marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Granular Materials https://www.youtube.com/watch?v=R7g6wdmYB78 marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Granular Materials https://www.youtube.com/watch?v=R7g6wdmYB78 marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Force networks : measurement via cross polarizers Hydrostatic pressure increases linearly in a regular fluid in equillibrium But not in a granular material! Bi et al, Nature 480 , 355 (2011) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Janssen effect: silo engineering Janssen, Experiments on corn Ovarlez et al, Phys. Rev. E., 67, 060302(R) (2003) pressure in silo cells (1895) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Janssen effect: Grünerløkka studenthus Credit: Dagsavisen Credit: Uniforum marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Janssen effect: experiment and theory marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Reynolds Dilatancy : pore-volume increases under shear marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Reynolds Dilatancy : pore-volume increases under shear Why walking on wet sand makes it dry https://www.youtube.com/watch?v=1ssTdOt9DKI marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Segregation : the Brazil-nut effect marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Segregation : the Brazil-nut effect Brazil Nut Effect https://www.youtube.com/watch?v=XTM-okBCX8U marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Spontaneous stratification and pattern formation Makse et al, Nature 386 , 379 (1997) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Spontaneous stratification and pattern formation Mathematical Impressions: Spontaneous Stratification https://www.youtube.com/watch?v=CpZaRn0Bez0 marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Other examples of pattern formation “Well, the stripes are easy but what Ripples in wind-blown sand. about the horse part ?” Ball, P. (2015), Phil. Trans. R. Soc. B, 370. - Alan Turing marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Other examples of pattern formation Ferrofluids Ferrofluids (Youtube  getferrite) (Youtube  Chemical Bouillon) Labyrinthine structures emerging from the slow drying of fluid-grain mixtures in confined geometries. Knudsen, H. et al., Phys. Rev. E, 77, 021301 (2008) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Other examples of pattern formation Labyrinth pattern during the drying of a granular suspension. Movie by Bjørnar Sandnes. Sandnes, B. et al. (2007), Phys, Rev. Lett., 99, 038001 (Youtube  Complex Flow Lab) marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Other examples of pattern formation Viscous fingering. Movie by Marcel Moura and Knut Jørgen Måløy. marcel.moura@fys.uio.no gaute.linga@mn.uio.no

marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Summary Pattern formation Measurements of force networks in porous media flows in granular materials via cross polarizers Viscous fingering Labyrinths in in non-deformable deformable media media Brazil-nut Spontaneous Janssen effect Reynolds dilatancy effect stratification marcel.moura@fys.uio.no gaute.linga@mn.uio.no

Check porelab.no/studies for MSc and PhD opportunities at PoreLab. marcel.moura@fys.uio.no gaute.linga@mn.uio.no