ABSTRACT
Researchers are looking to utilize nanofluids as a way to increase the efficiency in solar energy applications. Metallic particles are becoming popular because of the plasmonic characteristics allowing for more absorption. Only homogenous nanofluids for solar applications have been considered. This article proposes the use of a hybrid nanofluid containing multiple types of nanoparticles with water as the base fluid exposed to radiation. This hybrid mixture can utilize a broader wavelength spectrum and absorb more heat. Recipes for combining gold, copper, aluminum, graphite, and silicon dioxide gold nanoparticles into water are given graphically and numerically for different concentrations, diameters, and container heights.
Nomenclature
area | = | integrated area, W/m2 |
A | = | integrated area, W/m |
Areatot | = | integrated area, W/m |
c0 | = | speed of light, m/s |
Cabs | = | cross section, m2 |
d | = | diameter, m |
database | = | database of particles |
f | = | fraction emissive power |
h | = | Planck’s constant J s |
H | = | height, m |
I | = | intensity, W/m2 |
k | = | wavenumber, m−1 |
kB | = | Boltzmann constant, m2 kg/s2 K |
L | = | length, m |
n | = | number of particles in fluid |
N | = | number in combination |
P | = | polarizability constant |
Pj | = | percentage of concentration |
qr | = | radiation term, W/m2 |
Qabs | = | absorption coefficient |
input | = | input temperature |
j | = | type of nanoparticles |
max | = | maximum |
min | = | minimum |
p | = | particle |
S | = | graphite constant |
T | = | Temperature, K |
V | = | Volume, m3 |
y | = | direction, m |
α | = | polarizability |
= | damping term, s−1 | |
ε | = | permittivity |
ε∞ | = | permittivity of the bulk particle |
κ | = | absorption index |
λ | = | wavelength, m |
σ | = | absorption coefficients, m−1 |
φ | = | volume faction |
ω | = | frequency, s−1 |
Subscripts | = | |
abs | = | absorption |
b | = | blackbody |
f | = | fluid |
plasma | = | plasma |
S | = | graphite constant |
tot | = | total |
λ | = | wavelength |
Nomenclature
area | = | integrated area, W/m2 |
A | = | integrated area, W/m |
Areatot | = | integrated area, W/m |
c0 | = | speed of light, m/s |
Cabs | = | cross section, m2 |
d | = | diameter, m |
database | = | database of particles |
f | = | fraction emissive power |
h | = | Planck’s constant J s |
H | = | height, m |
I | = | intensity, W/m2 |
k | = | wavenumber, m−1 |
kB | = | Boltzmann constant, m2 kg/s2 K |
L | = | length, m |
n | = | number of particles in fluid |
N | = | number in combination |
P | = | polarizability constant |
Pj | = | percentage of concentration |
qr | = | radiation term, W/m2 |
Qabs | = | absorption coefficient |
input | = | input temperature |
j | = | type of nanoparticles |
max | = | maximum |
min | = | minimum |
p | = | particle |
S | = | graphite constant |
T | = | Temperature, K |
V | = | Volume, m3 |
y | = | direction, m |
α | = | polarizability |
= | damping term, s−1 | |
ε | = | permittivity |
ε∞ | = | permittivity of the bulk particle |
κ | = | absorption index |
λ | = | wavelength, m |
σ | = | absorption coefficients, m−1 |
φ | = | volume faction |
ω | = | frequency, s−1 |
Subscripts | = | |
abs | = | absorption |
b | = | blackbody |
f | = | fluid |
plasma | = | plasma |
S | = | graphite constant |
tot | = | total |
λ | = | wavelength |
Acknowledgments
Thanks to Alliances for Graduate Education and the Professoriate (AGEP) and Dr. Bayazitoglu’s heat transfer lab at Rice University for their contribution.