TITLE

Comment on “Particle concentration and tube size dependence of viscosities of Al2O3—water nanofluids flowing through micro- and minitubes” [Appl. Phys. Lett. 91, 243112 (2007)]

AUTHOR(S)
Ayela, F.; Chevalier, J.
PUB. DATE
February 2009
SOURCE
Applied Physics Letters;2/9/2009, Vol. 94 Issue 6, pN.PAG
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
In a recent letter, Jang et al. [Appl. Phys. Lett. 91, 243112 (2007)] reported an anomalous viscosity enhancement for very dilute nanofluids (0.02–0.3 vol %). They claim that the size of nanoparticles relative to the tube size has a profound influence on the viscosity of the nanofluids flowing through micro- and minichannels in a fully developed laminar flow. The authors used Al2O3 nanoparticles with a mean diameter of 30±5 nm dispersed in water. We believe that their interpretation of these experiments is questionable because they have underestimated the importance of experimental uncertainties. A conventional explanation of their results can be drawn from simple hypothesis.
ACCESSION #
36609547

 

Related Articles

  • Classroom. Chattopadhyay, R. // Resonance: Journal of Science Education;Feb2008, Vol. 13 Issue 2, p81 

    The article reports on the study which investigates the viscosity and flow velocity of glass vessels using Poiseuille's equation at Presidency College in Calcutta, India. It reveals that the percentage deviation is -1.03 percent which corresponds with the validity of the above value of the...

  • Effect of viscous dissipation on laminar mixed convection in a horizontal channel. El-Din, M M Salah // Proceedings of the Institution of Mechanical Engineers -- Part E;2002, Vol. 216 Issue 3, p167 

    Laminar mixed convection in a horizontal channel is studied analytically in the fully developed region when the effect of viscous dissipation cannot be neglected. Two kinds of thermal boundary conditions are considered: uniform wall temperatures and uniform wall heat fluxes. Velocity and...

  • Transition to turbulence of the flow in a straight pipe downstream of a helical coil. Hon, R.; Humphrey, J. A. C. // Physics of Fluids;Oct99, Vol. 11 Issue 10, p2993 

    Explores the transition to turbulence of the flow in a straight pipe downstream of a long helical coil where the flow has previously laminarized. Coil diameter to curvature ratio; Reynolds number of the flow; Kinematic viscosity; Coiled pipe geometry; Cross-stream secondary motion induced by...

  • Flow and heat transfer of a couple-stress fluid sandwiched between viscous fluid layers. Umavathi, J. C.; Chamkha, A. J.; Manjula, M. H.; Al-Mudhaf, A. // Canadian Journal of Physics;Jul2005, Vol. 83 Issue 7, p705 

    The problem of steady laminar fully developed flow and heat transfer in a horizontal channel consisting of a couple-stress fluid sandwiched between two clear viscous fluids is analyzed analytically. The fluids in all regions are assumed to be incompressible, immiscible, and the transport...

  • SÄ°LÄ°NDÄ°RÄ°K BORULARDA TEK FAZLI MANYETO HÄ°DRODÄ°NAMÄ°K AKIÅžIN TEORÄ°K VE DENEYSEL OLARAK Ä°NCELENMESÄ°. Racabovadıloğlu, Ziyaddin // Teknoloji;Jan-Jun2002, Vol. 5 Issue 1/2, p43 

    In this study, the effect of a magnetic area normal to a cylindrical pipe made by a nonmagnetic material on one phased laminar magneto-hydrodynamic flow has been investigated as theoretical and experimental bases. In theoretical study, while decreasing hydrodynamic forces into average values by...

  • LIQUID/LIQUID VISCOUS DISPERSIONS WITH A SMX STATIC MIXER. Fradette, L.; Tanguy, P.; Li, H.-Z.; Choplin, L. // Chemical Engineering Research & Design: Transactions of the Inst;Mar2007, Vol. 85 Issue 3, p395 

    A SMX static mixer was used to disperse highly viscous Newtonian liquids into less viscous, Newtonian and non-Newtonian fluids without surfactants. The investigation covered the effect of the dispersed phase volume fraction, the viscosity ratio between the phases, the mixer length and the power...

  • Calculation of Oscillations of a Cylindrical Pendulum in a Cavity Filled with a Viscous Fluid with the Use of Sliding Multiblock Grids. Baranov, P. A.; Isaev, S. A.; Kudryavtsev, N. A.; Kharchenko, V. B. // Journal of Engineering Physics & Thermophysics;Sep/Oct2003, Vol. 76 Issue 5, p1024 

    The characteristics of the oscillations of a cylindrical pendulum in a square cavity filled with an incompressible viscous fluid have been forecast on the basis of the joint numerical modeling of two‐dimensional unsteady laminar flow around a circular cylinder with the use of movable...

  • RESEARCH OF NONSTATIONARY LAMINAR FLOW OF DECELERATING VISCOUS FLUID IN CIRCULAR CYLINDRICAL COMMUNICATIONS. Tokmajyan, H. V.; Sarukhanyan, T. A. // Advanced Materials Research;2014, Issue 1020, p361 

    Flow of viscous fluid in automation and control hydraulic systems usually is nonstationary. In such conditions research of viscous fluid unstable flow are important first of all for obtaining hydraudynamic parameters of flow and secondly, they will enable to design the system accurately and...

  • A Wind Tunnel Study of the Effects of Turbulence on the Growth of Cloud Drops by Collision and... Vohl, O.; Mitra, S.K. // Journal of the Atmospheric Sciences;12/15/99, Vol. 56 Issue 24, p4088 

    Focuses on a study which investigated the growth of single drops by collision coalescence with small droplets in laminar and turbulent flow. Experimental setup of the study; Examples of typical droplet spectra; Turbulent conditions of the study; Conclusions.

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics