THW - Nanofluids

Thermal Conductivity

THW - Nanofluids

Thermal Conductiivity - Nanofluids

Method employed

The enhancement of the thermal conductivity of fluids when a small portion of nanoparticles is added, is currently under investigation. Measurements are very interesting and the work is progressing fast.

So far it has been found that most of the high thermal conductivity enhancement published ιin literature is attributed to improper use of techniques, or to the use of commercial instruments not suitable for such fmeasurements. A transient hot-wire instrument (THW) was built specifically for this task, and mesurements carried out indicated that the enhancement of the thermal conductivity in most cases, is similar to that predicted by the theoretical Hammilton-Crosser Maxwellian model.
Furthermore measurements of the viscosity of the same systems showed that the gain in thermal conductivity could easily be overcome by the loss attributed to the increase in viscosity.

Tertsinidou G., Assael M.J., Wakeham W.A., “The Apparent Thermal Conductivity of Liquids Containing Solid Particles of Nanometer Dimensions: A Critique”, Int. J. Thermophys. On-line (2015).

Antoniadis K.D., Tertsinidou G.J., Assael M.J., Wakeham W.A., "Necessary conditions for accurate, transient hot-wire measurements of the apparent thermal conductivity of nanofluids are seldom satisfied", Int. J. Thermophys. 37:78-100 (2016).

Tertsinidou G.J., Tsolakidou Ch., Pantzali M., Assael M.J., Colla L., Fedele L., Bobbo S., and Wakeham W.A., “New measurements of the apparent thermal conductivity of nanofluids and investigation of their heat transfer capabilities”, J. Chem. Eng. Data 62:491–507 (2017) Editor’s Choice OpenAccess

Ranges & uncertainties

Systems examined so far refer to Cuo, Al₂O₃, TiO₂ and Carbon Multi-Walled Nanotubes (C-MWNT) in water or ethylene glycol in the presence of various dispersants.

The temperature range examined so far is near room temperature, while the uncertainty of the measurements is better than 2%.

Systems sudied so far

Tertsinidou G.J., Tsolakidou Ch., Pantzali M., Assael M.J., Colla L., Fedele L., Bobbo S., and Wakeham W.A., “New measurements of the apparent thermal conductivity of nanofluids and investigation of their heat transfer capabilities”, J. Chem. Eng. Data 62:491–507 (2017) Editor’s Choice OpenAccess
Antoniadis K.D., Tertsinidou G.J., Assael M.J., Wakeham W.A., "Necessary conditions for accurate, transient hot-wire measurements of the apparent thermal conductivity of nanofluids are seldom satisfied", Int. J. Thermophys. 37:78-100 (2016).
Tertsinidou G., Assael M.J., Wakeham W.A., “The Apparent Thermal Conductivity of Liquids Containing Solid Particles of Nanometer Dimensions: A Critique”, Int. J. Thermophys. On-line (2015).
Assael M.J., Metaxa I.N., Kakosimos K., and Konstandinou D., “Thermal conductivity of nanofluids - Experimental and Theoretical”, Int. J. Thermophys. 27:997-1017 (2006).
Assael M.J., Metaxa I., Arvanitidis J., Christofilos D., and Lioutas C., “Thermal Conductivity Enhancement in Aqueous Suspensions of Carbon Multi-Walled and Double-Walled Nanotubes in the Presence of two Different Dispersants”, Int. J. Thermophys. 26:647-664 (2005).
Assael M.J., Chen C.-F., Metaxa I.N., and Wakeham W.A., "Thermal Conductivity of Nanofluids", Thermal Conductivity 27/Thermal Expansion 15, 153-164 (2004).
Assael M.J., Chen C.-F., Metaxa I., and Wakeham W.A., "Thermal Conductivity of Carbon Nanotube Suspensions in water", Int. J. Thermophys. 25:971-985 (2004)