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ICNMRE SAFI/MOROCCO July 5-8 2010. Influence of NP size and concentration on the physical properties of Glycerol/Cu 2 O nanofluid. R. HEYD CRMD/UMR 6619 – ORLÉANS/France LPN/ENS – Marrakech/Maroc FFSM/Cadi Ayyad University – Marrakech/Maroc. The problem.
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ICNMRE SAFI/MOROCCO July 5-8 2010 Influence of NP size and concentration on the physical properties of Glycerol/Cu2O nanofluid R. HEYD CRMD/UMR 6619 – ORLÉANS/France LPN/ENS – Marrakech/Maroc FFSM/Cadi Ayyad University – Marrakech/Maroc
The problem • Liquids are used as heat carriers in: Diesel engine Solar hot water panels
The problem Thermal conductivities, (λ) at RT. • Fourier’s law: • How to combine: • flow properties of liquids & • high thermal conductivity of solid metals. • Using a new class of nanocomposites: liquid/solid?
Cuprite Nanoparticles/Nanofluid • Cu2O nanoparticles: • Two extreme diameters were used: synthesized by reverse micelles at CRMD/Orléans (see poster for more details) purchased from Sigma-Aldrich
Cuprite Nanoparticles/Nanofluid • Nanofluid synthesis: = Glycerol (biocompatible and anti-freezing liquid) + Cu2O nanoparticles in stable suspension • Objectives: Test the influence of Cu2O NP on Glycerol’s transport properties, as a function of: • NP size • NP concentration
Rheological properties • Experimental/Results • Kinexus rotational Rheometer • General Arrhenius Law:
Rheological properties • Experimental/Results • Variations of relative viscosity with NP volume fraction at RT
Rheological properties • Summary: • The addition of NP slightly increases the viscosity, • NP size has little influence, • The studied nanofluids tested exhibit the same general Arrhenius law as glycerol, • Viscosity increases with the NP volume fraction ϕ.
Thermal properties • Experimental: technique Ref : Development of absolute hot-wire anemometry by the 3ω method, R. Heyd et al, 044901. In Review of Scientific Instruments 81 (4), 2010.
Thermal properties • Results: Investigations of thermal conductivity and viscosity of nanofluids, S.M.S. Murshed, K.C. Leong, C. Yang, International Journal of Thermal Sciences 47 (2008) 560–568.
Thermal properties • Results:
Thermal properties • Summary: • Linear variation of the effective thermal conductivity of nanofluids with temperature, • Significant enhancement of the thermal conductivity with volume fraction and with NP size.
Conclusion & Perspectives • The influence of increasing temperature on NP Brownian motion is: • Decreasing the viscosity of glycerol and consequently that of the nanofluid • Increasing the micro-convective contribution of the NP and consequently the thermal conductivity increases • Influence of NP shape, size and interfacial layer on transport coefficients has to be taken into account. • Investigation of electrical properties of nanofluids as a function of NP. • Development of a microscopic model to better describe transport phenomena in nanofluids.