Thermophysical and rheological properties of unitary and hybrid nanofluids

Mercan H. , Celen A., Taner T.

in: Advances in Nanofluid Heat Transfer, Hafiz Muhammed Ali, Editor, Elsevier Science, Oxford/Amsterdam , Amsterdam, pp.95-129, 2022

  • Publication Type: Book Chapter / Chapter Research Book
  • Publication Date: 2022
  • Publisher: Elsevier Science, Oxford/Amsterdam 
  • City: Amsterdam
  • Page Numbers: pp.95-129
  • Editors: Hafiz Muhammed Ali, Editor


When a thermal system operates, the heat is exchanged by using a working
fluid. The working fluid of such systems can be a single fluid or a mixture
or a nanosuspension. Ethylene glycol, ethanol, water, engine oil, ammonia,
and halogenated hydrocarbons are typical examples of working fluids frequently
used in industrial applications. Thermophysical properties of the working
fluid determine the efficiency limits of a thermal system and the desire for
a more efficient system leads researchers to engineer a better performing
working fluid. The addition of nanosize particles with a considerably low
concentration enhanced the thermophysical properties, such as thermal conductivity,
specific heat capacity, and convective heat transfer coefficient significantly.
The common nanoparticles are a range of metals, metal oxides, metal
carbides, nanotubes, and carbon. If a single type of nanoparticle is added to
the base fluid the blend is called a unitary nanofluid, if more than one type of
nanoparticle is added; the blend is called a hybrid nanofluid. Although nanofluids
are sophisticated suspensions, spreading, stability, chemical and thermal
suitableness of the nanoparticles should be guaranteed during the preparation
procedures. To maintain this preferred elongated stability, the selection of a
suitable concentration accompanied with surfactants addition and/or sonication
procedures are commonly used remedies in the literature.