Download - An Introduction to the NanoFluid
An Introduction to the
NanoFluid
By
Amin Behzadmehr
Hassan Azarkish
Introduction
Nanofluids are a relatively new class of fluids which consist of abase fluid with nano-sized particles (1–100 nm) suspended withinthem. It is introduced by choi on Argonne National Laboratory at1995.
-Heat Transfer Enhancement-Heat Transfer Enhancement
Comparison of the thermal conductivity of common liquids, polymers and solids.
(D. Wen et al. Particuology 7 (2009) 141–150)
Compared to conventional solid-liquid suspensions for heat transfer
intensifications, properly engineered thermal nanofluids possess the
following advantages:
1. High specific surface area and therefore more heat transfersurface between particles and fluids.
2. High dispersion stability with predominant Brownian motion of
Advantages of nanofluids
2. High dispersion stability with predominant Brownian motion ofparticles.
3. Reduced pumping power as compared to pure liquid to achieveequivalent heat transfer intensification.
4. Reduced particle clogging as compared to conventionalslurries, thus promoting system miniaturization.
5. Adjustable properties, including thermal conductivity andsurface wettability, by varying particle concentrations to suitdifferent applications.
Applications of nanofluids
•Transportation (Engine cooling/vehicle thermal management)
•Electronics cooling
•Defense
•Space
•Nuclear systems cooling•Nuclear systems cooling
•Heat exchanger
•Biomedicine
•Other applications (heat pipes, fuel cell, Solar water heating,
chillers, domestic refrigerator, Diesel combustion, Drilling,
Lubrications, Thermal storage,…)
Production of nanoparticles and nanofluids
NanoparticlesPhysical methods (Grinding methods, Inert Gas Condensation, …)
Chemical methods (Chemical precipitation, Chemical Vapor Deposition,
Micro-emulsions, spray pyrolysis, thermal spraying,…)
NanofluidsNanofluidsThe one-step methodsimultaneously makes and disperse the nanoparticles directly into a base fluid
prevent oxidation of pure metal particles
non commercial
The two-step methodproduced the nanoparticles and dispersed them into a base fluid
Research and industrial applications
Researches
Experimental ResearchesThermal properties
Heat transfer correlations
Analytical ModelsAnalytical ModelsThermal properties
Similarity solutions
Numerical ResearchesSingle-phase
Two-phaseGrowth of publications by the nanofluids
community.
(D. Wen et al. Particuology 7 (2009) 141–150)
Convective heat transfer correlations for nanofluids.
Sampels of theoretical investigations in convective heat transfer of nanofluids.
Experimental research on nanofluid thermal conductivityEffect of particle volume concentration
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of particle material
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of particle size
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of particle shape
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of base fluid
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of temperature
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental research on nanofluid thermal conductivityEffect of PH
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Nanofluids reported in literature
Experimental researches on heat transfer
Laminar flow
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental researches on heat transfer
Turbulent flow
W. Yu, D.M. France, S.U.S. Choi, and J.L. Routbort
Energy Systems Division, Argonne National Laboratory
Experimental researches on heat transfer
Natural convection
(N. Putra et al. Heat and Mass Transfer 39 (2003) 775–784)
Challenges of nanofluids
•lack of agreement of results obtained by different researchers
•lack of theoretical understanding of the mechanisms
responsible for changes in properties
•poor characterization of suspensions
•stability of nanoparticles dispersion•stability of nanoparticles dispersion
•Increased pressure drop and pumping power
•Nanofluids thermal performance in turbulent flow and fully
developed region
•Higher viscosity, Lower specific heat
•High cost of nanofluids
•Difficulties in production process
Stability of nanoparticles dispersion
Samples of Al2O3 nanofluids (without any stabilizer)
stability change with time
(R. Saidura et al. Renewable and Sustainable Energy Reviews 15 (2011) 1646–1668)
Stability of nanoparticles dispersion
The sedimentation of diamond nanoparticles at settling times of
(a) 0 min, (b) 1min, (c) 2min, (d) 3min, (e) 4min, (f) 5min, and (g) 6min
(R. Saidura et al. Renewable and Sustainable Energy Reviews 15 (2011) 1646–1668)
Nanoparticle agglomerates
(N. Putra et al. Heat and Mass Transfer 39 (2003) 775–784)
Part ‖
Research activities in nanofluidlaboratory
in Mechanical Engineering Department ofin Mechanical Engineering Department of
University of Sistan and Baluchestan
Researches
Numerical Works
Analytical Models
Experimental InvestigationsExperimental Investigations
Numerical Researches
� Single Phase approach
� Two-Phase approach
Single Phase approach
Two-Phase approach
� Mixture model
� Eulerian – Eulerian
� Eulerian-Lagrangian
Mixture model
Continuity
Momentum
Energy
Volume fraction
Eulerian – Eulerian
Continuity
Momentum Eq. in x directionMomentum Eq. in x direction
Eulerian – Eulerian
Momentum Eq. in y direction
Eulerian – Eulerian
Energy Equation
Eulerian-Lagrangian
Continuity
Momentum
Energy
Lagrangian for the particles
Some of the Numerical Results
Comparison of measured and calculated Nusselt numbers for a nanofluid flow.
Behzadmehr et al. 2007, International Journal of Heat & Fluid Flow, Vol.28, pp. 211-219
Some of the Numerical Results
Axial evolution of the centerline turbulent kinetic energy
Behzadmehr et al. 2007, International Journal of Heat & Fluid Flow, Vol.28, pp. 211-219
Fully developed peripheral average Nusselt number at different Grashof numbers: (a) Re = 300
(De = 83), (b) Re = 900 (De = 249).
Fully developed peripheral average skin friction coefficient at different Grashof numbers: (a) Re = 300
(De = 83), (b) Re = 900 (De = 249).
A. Akbarinia, A. Behzadmehr, 2007, Applied Thermal Engineering, Vol. 27, pp. 1327-1337
S. Mirmasoumi , A. Behzadmehr, 2008, International Journal of Heat & Fluid Flow, Vol. 29, pp.557-566
O. Gaffari, A. Behzadmehr, H. Ajam, 2010, International Communications in Heat and Mass Transfer 37 1551–1558
A new model for calculating the effective viscosity of nanofluids
Brownian motion, velocity between the base fluid and nanoparticles
Temperature, Mean nanoparticle diameter, Nanoparticle volume fraction,
Nanoparticle density and base fluid physical properties.
Analytical Models
N. Masoumi, N. Sohrabi, A. Behzadmehr, 2009, JOURNAL OF PHYSICS D: APPLIED PHYSICS 42
Comparison of the predicted relative
viscosity with the experimental and
other available models in the literature
for the Al2O3–H2O nanofluid at
(a) dp = 36 nm,
(b) dp = 28 nm
(c) dp = 13 nm.
Comparison of the predicted effective
viscosity with the experimental and
other available models in the literature
for the CuO–H2O nanofluid.
A Simple Analytical Model for Calculating the Effective ThermalConductivity of Nanofluids
•Conduction heat transfer caused by a solid-like nanolayer that covers
the nanoparticle.
•A convective heat transfer caused by the relative motion between the
Analytical Models
•A convective heat transfer caused by the relative motion between the
nanoparticle and the surrounding base fluid.
This equation presents the effective thermal conductivity as a function
of the thermal conductivity of nanoparticles, base fluid, nanoparticle
mean diameter, temperature, and solid-like nanolayer
N. Sohrabi, N. Masoumi, A. Behzadmehr, S.M.H. Sarvari, 2010, Heat Transfer - Asian Research Vol. 10, pp 141-150
Nanoparticle, nanolayer, and
surrounding base fluid arrangement.
Variations of the effective thermal conductivity with temperature:
(a) Al2O3–EG, (b) CuO–water
Experimental Investigations
� Single phase heat exchanger
� Boiling
� Stability
Thanks