Ancey, C.

Andreini, N.

Rentschler, M.

Wiederseiner, S.

Infoscience - École polytechnique fédérale de Lausanne

Velocity and concentration profilesmeasurements in concentrated particlesuspensionsS. Wiederseiner, N. Andreini, C. Ancey & M. RentschlerLaboratoire d’Hydraulique EnvironnementaleEcole polytechnique fe´de´rale de LausanneIMA conference on dense granular flowsJanuary 5-9, 2008 - CambridgeFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsGeophysical flowsFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsGeophysical flowsComplex fluidsParticlesMaterialShapeSizedistributionRoughnessInterstitial fluidsViscosity⇒How do we measure the rheo-logical properties ?Yield stressShear-thinning,Shear-thickeningThixotropy, rheopexyFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsGeophysical flowsComplex fluidsParticlesMaterialShapeSizedistributionRoughnessInterstitial fluidsViscosity⇒How do we measure the rheo-logical properties ?Yield stressShear-thinning,Shear-thickeningThixotropy, rheopexyFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConsequences for the rheologist1(TΩ)99K(τγ˙)2 Wide gap(because of the sizedistribution)T : Total TorqueΩ : Angular velocityτ : shear stressγ˙ : shear rate⇒Solve the Couetteinverse problemτ(r) =T2pir2hΩ =∫ RoutRinγ˙(r)rdrr : Radiush : Height of fluidRin/out : Radius of the inner/outer cylinderFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsAssociated Couette inverse problemSolving methods :Infinite series approachγ˙(τ) = ωln s[1 + ln s d lnωd ln τ +(ln s)23ωd2ωd(ln τ)2 + ...]Least square approach min ||ω − K γ˙||Projection approach < K γ˙,ui >=< ω, ui >Adjoint operator approach γ˙ =Pi∈J< K γ˙,ui > ΨiK ⋆ui = ΨiFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConsequences for the rheologistSolving methods :Mooney (1931)Krieger & Maron (1952)Krieger & Elrod (1953)Krieger (1968)Yang & Krieger (1978)Mac Sporran (1986)(1989)Nguyen (1992)Yeow (2000)Ancey (2005)De Hoog & Anderssen (2005)(2006)Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConsequences for the rheologistExample : an artificial Herschel-Bulkley fluid τ = τy + K γ˙ns = RinRout = 0.910−3 10−2 10−1 100 101050100150200250300350  krieger52krieger53dehoog05−mpdehoog05−mmpdehoog05−ttfddehoog05−mttfddehoog05−ftfddehoog05−mftfdkrieger52krieger68macsporran86s0tikhonovτ [Pa]γ˙[s−1 ]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConsequences for the rheologistThe same fluid with a wide-gap geometrys = RinRout = 0.210−4 10−3 10−2 10−1 100 101 102050100150200250300350  krieger52krieger53dehoog05−mpdehoog05−mmpdehoog05−ttfddehoog05−mttfddehoog05−ftfddehoog05−mftfdkrieger52krieger68macsporran86s0tikhonovτ [Pa]γ˙[s−1 ]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsExample : a polymeric gelAncey, J.Rheology 49 (2005) 441-460Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsExample : a particle suspensionsAncey, J. Rheol. 45 (2001)1421-1439S : adimensionalized shear stressΓ : adimensionalized angular velocityFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsExample : a particle suspensionsAncey, J. Rheol. 45 (2001)1421-1439S : adimensionalized shear stressΓ : adimensionalized angular velocityAncey, J.Rheology 49 (2005) 441-460Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsShear localization ?Particle segregation ?Particle migration ?Ordering ?Particle roughness ?Particle Shape ?Slipping ?Do we measure material’s physical properties...... or disturbing effects ?Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsClassical and optical rheometryContinuummechanicsapproach⇓Classical rheometry⇓T and Ω⇓Solve the Couetteinverse problem⇓τ and γ˙Rheophysicalapproach⇓Clear suspensions⇓Particle motion(FPIV / FPTV)⇓Differentiate thevelocity profile⇓τ and γ˙Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsProperties of the suspensionsWhere do the properties come from ?Studied flowsOptical methods=⇒concentrated particlesuspensions(25mm thickness)Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsProperties of the suspensionsThe simplest complex fluidIso-index ⇒ transparencyIso-density ⇒ No gravity effectsMolecular tagging of the particles⇒ the laser excites fluorescenceParticles FluidShape : sphericalGranulometryThree fluids mixtureNewtonianViscosity : variableFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsProperties of the suspensionsNon colloidal and highly concentrated particlesuspensionsSpherical PMMA particles with adiameter of 50 to 350 µmMixture of three newtonian fluids(Lyon & Leal 1997)Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsProperties of the suspensionsWet sieving0 50 100 150 200 250 300 350 40000.10.20.30.40.50.60.70.80.91µ = 198µm, σ = 4.8µmsieved PMMAParticle Diameter [µm]raw PMMAµ = 168µm, σ = 54µmFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsDisturbing effectsTemperature and wavelength effectsTemperature effectsWavelength effectsFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsTemperature effectsTemperature effectsDensityRefractiveindexDensityofTritonX100[g/cc]Densityofdibromohexane[g/cc]Temperature [ ˚ C]∆ρ∆T = 1 [kg/m3 ˚ C]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsTemperature effectsTemperature effectsDensityRefractiveindex16 17 18 19 20 21 22 23 240.9980.99850.9990.999511.0005  Dibromohexane	 −3.6667e−04  1/°CUCON oil	          −3.4250e−04  1/°CTriton X100        −3.2083e−04  1/°CFit lineaireadimensionalizedrefractiveindex[-]Temperature [ ˚ C]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsTemperature effectsTemperature effects on light transmission                    PhotodetectorParticlesuspensionmore than 500 interfacespinholeMesurementLaser 532nmFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsTemperature effectsTemperature effects on light transmission18.5 19 19.5 20 20.5 21 21.5 22 22.50.50.550.60.650.70.75I Suspension/I fluid[−]Temperature [ ˚ C]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsWavelength effectsEffects of mismatch in the Refractive index ontransmission1.483 1.484 1.485 1.486 1.487 1.488 1.489 1.49 1.491 1.49200.10.20.30.40.50.60.7I suspension/I fluid[−]Refractive index n [-]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsWavelength effectsWavelength effectsFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsWavelength effectsWavelength effectsRGB picture with a color CCD camera :Blue component Red componentFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFPIV / FPTV techniquesMeasurement methodsFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFPIV / FPTV techniquesMeasurement methodsLASERSHEETFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFPIV / FPTV techniquesMeasurement methodsLASERSHEETCAMERAFILTERFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFPIV / FPTV techniquesMeasurement methodsFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsMeasurement setupThe setupFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFPIV ImagesFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsValidationValidation measurementsVθ(r) =Ar+ Br with A = R2inR2outΩR2out − R2in, B = R2inΩR2in − R2out0.012 0.014 0.016 0.018 0.02 0.022 0.024 0.026 0.028 0.0300.10.20.30.40.50.60.70.80.91             vθ theoreticalvr theoreticalvθ experimentalvr experimentalRinVθ,rVθ,in[−]Radial position [m]RoutFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsVelocity profile of concentrated suspensionsTime evolution of the suspension12 14 16 18 20 22 24 26 28 3000.20.40.60.81  after 1 hourafter 2 hoursafter 3 hoursafter 5 hoursRinVθ,rVθ,in[−]RoutRadial position [mm]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsVelocity profile of concentrated suspensionsBottom end effects10 15 20 25 3000.20.40.60.81  35mm from the bottom25mm from the bottom10mm from the bottomVθ,rVθ,in[−]Radial position [mm]Rin RoutFlows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsFlow curve derivationFlow curve comparison10−2 10−1 1000246810  velocity profilemacsporran86yeow00ancey05dehoog06other methodsγ˙[s−1 ]τ[Pa]Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConclusionFuture workWe want to use the same techniques to carry out experimentson the dam-break problem (sudden release of a finite volume offluid down a plane) and measure the cross-stream velocityprofile inside the bulk within the head.Flows Rheology and Rheophysics Concentrated particle suspensions Measurement method ResultsConclusionAcknowledgmentChristophe AnceyNicolas Andreini, Martin RentschlerThe Swiss National Science FoundationIso-index ⇒ transparencyIso-density ⇒ No gravitation effectsnot toxicParticles FluideSphericityGood optical propertiesGranulometryFluorecent moleculartaggingNo evaporationWet the PMMAShould not disolve PMMALow absorptionNo excitationVariable viscosityFluidesLyon (1997)DibromohexaneTriton X 100Huile UCON 75HTransparent concentrated noncolloidalsuspensionsSpherical particles : 200to 600 µmIso-index andiso-density fluid mixtureWhy Rhodamine 6G ?How much rhodamine 6G ?High concentration⇓More fluorescence⇓COMPROMIS⇑Lower effect on the refractive index⇑Low concentrationProduit brutProduit tamisage par voie humide dans del’ ?thanolREPRODUCTIBILITEChoix de la Rhodamine 6GExcellent efficacit ?suffisamment faible ”Stokes shift”Suspension propertiesIso-index ⇒ transparencyIso-density ⇒ No gravitation effectsNon toxicParticules FluideSphericityGood optical propertiesGranulometryFluorecent moleculartaggingNo evaporationWet the PMMAShould not disolve PMMALow absorptionNo excitation

Velocity and concentration profiles measurements in concentrated particle suspensions.

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Velocity and concentration profiles measurements in concentrated particle suspensions.

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