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Salim
a Ra
faï
Labo
ratoire
Interdisc
iplinaire de Ph
ysique
Univ. Greno
ble I / CNRS
Plankton blooming Jacques Descloitres, MODIS Rapid
Response Team, NASA/GSFC
BioconvecMon or “slow turbulence” Dombrowski et al. Phys Rev LeQ 2004
Recent reviews: MarcheV et al 2013, Ramaswamy 2010, Lauga & Powers 2009
Chlamydomonas Reinhard0i quasi spherical
10 µm unicellular velocity ~ 10 radius . s-‐1
« synchronisable »
sperm cell paramecie bacillus subMlis E-‐coli
Microswimmers (living organisms)
Chlamydomonas Reinhard0i quasi spherical
10 µm unicellular velocity ~ 10 radius . s-‐1
« synchronisable »
Microswimmers (living organisms)
0.2 s.
temps réel
A complex swimming dynamics
20ms
2s
1 mm, 20 s 60 µm, 1s
• Garcia, Berti, Peyla & Rafai, Phys. Rev. E (R) (2011)
pusher type swimmer puller type swimmer
Fluid flow (Stokes) around a swimmer
u(r) = p8πηr3
(3cos2θ −1)far field
Numerical simulaMons Fluid ParMcle Dynamics Tanaka 2D (PRL 2000), Decoene 2D (Math. Mod. Nat. Phen 2011) Peyla 3D (EPL 2007)
Phantom flagella V. Mehandia and P.R. NoQ J. of Fluid Mech. 2008
Numerics
Shearthinning behaviour:: Compe00on between shear flow and swimming
ηeff = η0 (1-‐ϕ/ϕm) –αϕm Krieger & Dougherty 1959
α = 2.5 (dead cells) α = 4.5 (swimming cells)
EffecMve viscosity as a funcMon of volume fracMon S.Rafaï, L.Jibuti, and P.Peyla, Phys. Rev. Lett. (2010)
Rheology of a puller-‐type suspension
Phantom flagella Mehandia & NoQ J. of Fluid Mech. 2008
Numerical simulaMons Fluid ParMcle Dynamics
Tanaka 2D (PRL 2000), Decoene et al. 2D
(Math. Mod. Nat. Phen 2011) Peyla 3D (EPL 2007)
Rheology of a puller-‐type suspension
complementary observaMon S.Rafaï, L.Jibuti, and P.Peyla, Phys. Rev. Lett. (2010)
resistance to rotaMon consistent with increase of viscosity L.Jibuti, S. RafaÏ, P.Peyla J. Fluid Mech. 2012
anisotropy of orientaMon needed to explain the results not gravity: M. Mussler, S. Rafaï, P.Peyla & C. Wagner EPL 2013
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X Component of the velocity
X Component of the velocity
Phototaxis: Biaised swimming in presence of light y (µm)
x (µm)
X
x (µm)
y (µm)
Light biaised trajectories Trajectories in absence of biais vx(µm/s)
vx(µm/s)
Mme t=0 : Light ON X
Mme (s) Mme (s)
10 frames 4ms apart, Vmax=27 Vswim
same condiMons + light upstream
1 mm
1 mm
Spontaneous focusing when light is upstream
reminiscent of Kessler, Nature 1985
on-‐off experiments Microswimmer velocity controls the dynamics
X X
A reversible effect
Half band
width (µ
m)
Time (s)
ψ(r,t)
ψ(r, t) =ψ0 + ω(r, t ')dt '0
t
∫with
r
z
θ
Flow in a pipe & swimming: a simple non-‐linear model
r/R
z/R
R
drdt=V0 sin
dzdt=Vz (r)+V0 cos ψ(r,t)
(r,t)=Vmax r(t)R2
ω
Vz(r)=Vmax (1- r2
R2 )
V0
Poiseuille flow:
Swimming velocity
2R ω
ω
2R
A simple mecanism: Flow in a pipe & swimming: a simple non-‐linear model
Garcia, Rafaï & Peyla, Phys. Rev. Lett. (2013)
hQp://www.mvm.uni-‐karlsruhe.de
Any help for biofuel producMon?
PotenMal applicaMons: v concentraMon and separaMon è
biofuels, H2 production v detecMon of pollutants
h:p://www.mvm.uni-‐karlsruhe.de
Large scale setup
People: o Philippe Peyla, Prof. o Michaël Garcia, PhD (2009-‐2013) o Levan JibuM, PhD (2008 – 2011) o Stefano BerM, Post-‐Doc 2008 o Xabel Garcia, Master 2011 o MaQhieu MarMn, PhD (2014 -‐ o Ling Qi, Master 2013 o coll: ChrisMan Wagner (Prof Saarbruck), MaQhias Mussler (PhD, Saarbruck)
Fundings: • Région Rhône-‐Alpes/ programme Cible • ANR JCJC MicMacSwim 2012-‐2015 • Labex Tec 21 • Université Franco-‐Allemande
18
LabEdž!Tec!21!–!1ère!journée!«!Méthodes!numériques!»!Vendredi!7!Février!2014!
Amphi!K118!–!LEGI!bâtiment!K!
8h30:!Session!1!:!Principales!méthodes!numériques!:!principe,!potentiel,!développements!
récents,!verrous!(15’+5’)!
! 8h30!:!Méthode!des!éléments!finis!+!SPH!(Stéphane!Grange!Ͳ!3SR!&!Ph.!Larroudé!Ͳ!LEGI)!! 8h50!:!Volume!finis!et!Différences!fines!!(Christophe!Corre!et/ou!Eric!Goncalves!Ͳ�LEGI)!! 9h10!:!Méthode!éléments!discrets!et!Lattice!Botzmann!(Bruno!Chareyre!et/Žu!Vincent!Richefeu!Ͳ3SR)!
9h30!–!9h50!:!Pause!
9h50!:!Session!2!:!Focus!sur!certaines!applications!(présentations!«!Flash!»)!:!problématiques!F!
enjeux!–!verrous!(6’+6’)!
Eléments!finis!/!SPH!:!
• 9h50!:!Méthode!aux!Elements!Finis!avec!Points!d'Intégration!Lagrangiens!!(Frédéric!Dufour!–!3SR)
• 10h12!:!FEEL++!:!Finite!Element!Embedded!Library!in!C++!!(Mourad!Ismael�Ͳ!LIPhy)• 10H24!:!Simulations!d’écoulements!granulaires!et!viscoplastiques!à!surface!libre!par!méthode!SPH
(Guillaume!Chambon!F!IRSTEA)!
• 10H36!:!SPH!:!Applications!à!l’Environnement!Côtier!(Ph.!Larroudé!F!LEGI)
• 10H48!:!Méthode!spectrale!et!«!virtual!boundary!conditions!»!!(Achim!Wirth!F!LEGI)
• 11h00!:!Réduction!de!modèle!!(Guillaume!MaitreJean!F!LRP)
• 11h12!:!Régularisation,!rhéologie!granulaire!et!modèle!biFfluide!(Julien!Chauchat!F!LEGI)
Volumes!finis!/!différences!finis!:!
! 11h24!:!Modèles!aux!volumes!finis!pour!la!simulation!d’écoulements!gravitaires!rapides! (Dominique!
Laigle!F!IRSTEA)!
! 11h36!:!Simulation!des!écoulements!cavitants!en!turbomachines!(Régiane!Fortes!F!LEGI)!
! 11h48!:!Méthode!Level!set!!(Emmanuel!Maitre!F!LJK)!
! 12h00!:!Méthodes!hybrides!lagrangien/eulérien!pour!le!transport!turbulent!(GeorgesFHenri!Cottet!F!LJK)!
! 12h12!:!volumes!finis:!écoulement!compressible!F!systèmes!hyperboliques!!!(Eric!Goncalves!F!LEGI)!
12h24!:!Pause!déjeuner!
LabEdž!Tec!21!–!1ère!journée!«!Méthodes!numériques!»!Vendredi!7!Février!2014!
Amphi!K118!–!LEGI!bâtiment!K!
8h30:!Session!1!:!Principales!méthodes!numériques!:!principe,!potentiel,!développements!
récents,!verrous!(15’+5’)!
! 8h30!:!Méthode!des!éléments!finis!+!SPH!(Stéphane!Grange!Ͳ!3SR!&!Ph.!Larroudé!Ͳ!LEGI)!! 8h50!:!Volume!finis!et!Différences!fines!!(Christophe!Corre!et/ou!Eric!Goncalves!Ͳ�LEGI)!! 9h10!:!Méthode!éléments!discrets!et!Lattice!Botzmann!(Bruno!Chareyre!et/Žu!Vincent!Richefeu!Ͳ3SR)!
9h30!–!9h50!:!Pause!
9h50!:!Session!2!:!Focus!sur!certaines!applications!(présentations!«!Flash!»)!:!problématiques!F!
enjeux!–!verrous!(6’+6’)!
Eléments!finis!/!SPH!:!
• 9h50!:!Méthode!aux!Elements!Finis!avec!Points!d'Intégration!Lagrangiens!!(Frédéric!Dufour!–!3SR)
• 10h12!:!FEEL++!:!Finite!Element!Embedded!Library!in!C++!!(Mourad!Ismael�Ͳ!LIPhy)• 10H24!:!Simulations!d’écoulements!granulaires!et!viscoplastiques!à!surface!libre!par!méthode!SPH
(Guillaume!Chambon!F!IRSTEA)!
• 10H36!:!SPH!:!Applications!à!l’Environnement!Côtier!(Ph.!Larroudé!F!LEGI)
• 10H48!:!Méthode!spectrale!et!«!virtual!boundary!conditions!»!!(Achim!Wirth!F!LEGI)
• 11h00!:!Réduction!de!modèle!!(Guillaume!MaitreJean!F!LRP)
• 11h12!:!Régularisation,!rhéologie!granulaire!et!modèle!biFfluide!(Julien!Chauchat!F!LEGI)
Volumes!finis!/!différences!finis!:!
! 11h24!:!Modèles!aux!volumes!finis!pour!la!simulation!d’écoulements!gravitaires!rapides! (Dominique!
Laigle!F!IRSTEA)!
! 11h36!:!Simulation!des!écoulements!cavitants!en!turbomachines!(Régiane!Fortes!F!LEGI)!
! 11h48!:!Méthode!Level!set!!(Emmanuel!Maitre!F!LJK)!
! 12h00!:!Méthodes!hybrides!lagrangien/eulérien!pour!le!transport!turbulent!(GeorgesFHenri!Cottet!F!LJK)!
! 12h12!:!volumes!finis:!écoulement!compressible!F!systèmes!hyperboliques!!!(Eric!Goncalves!F!LEGI)!
12h24!:!Pause!déjeuner!