Povzetek
This paper unwraps nanofluids’ particle dynamics with
multi-walled carbon nanotubes (MWCNTs) in base fluids such as
acetone, water, and ethylene glycol. Having confirmed the
morphology and structure of the MWCNTs by field emission
scanning electron microscopy, X-ray diffraction, and Raman
spectroscopic analyses, the nanofluids are prepared in three different concentrations. The nonzero absorbance at the laser wavelength, revealed through the UV−visible spectrum, makes the thermal diffusivity study of the sample by the sensitive nondestructive single beam thermal lens (TL) technique possible. The TL signal analysis by time series and fractal techniques divulges the complex particle dynamics, through phase portrait, sample entropy, fractal dimension, and Hurst exponent. The study unveils the effect of the amount of nanoparticles and the viscosity of the medium on thermal diffusivity and particle dynamics. The observed inverse relation between thermal diffusivity and viscosity is in good agreement with the
Sankar−Swapna model. The complexity of particle dynamics in MWCNT nanofluids reflected through sample entropy, and fractal
dimension shows an inverse relation to the base fluid’s viscosity. This paper investigates the role of viscosity of the base fluid on particle dynamics and thermal diffusivity of the nanofluid to explore its applicability in various thermal systems, thereby suggesting a method to tune the sample entropy through proper selection of base fluid.
Ključne besede
MWCNT;thermal lens;fractals;nonlinear time series;phase portrait;sample entropy;
Podatki
Jezik: |
Angleški jezik |
Leto izida: |
2021 |
Tipologija: |
1.01 - Izvirni znanstveni članek |
Organizacija: |
UNG - Univerza v Novi Gorici |
UDK: |
54 |
COBISS: |
112981763
|
ISSN: |
2574-0970 |
Št. ogledov: |
577 |
Št. prenosov: |
0 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
URN: |
URN:SI:UNG |
Vrsta dela (COBISS): |
Delo ni kategorizirano |
Strani: |
str. 3416-3425 |
Letnik: |
ǂVol. ǂ4 |
Zvezek: |
ǂiss. ǂ4 |
Čas izdaje: |
Apr. 2021 |
DOI: |
10.1021/acsanm.0c03219 |
ID: |
15766861 |